Rapid Review Path Q's 2
Complete List of Terms and Definitions for Rapid Review Path Q's 2
| Terms | Definitions |
|---|---|
| Rusty sputum | Strep pneumo |
| Hepatosplenomegaly, osteoporosis, neurologic symptoms. Glucocerebroside deficiency. Crinkled tissue paper cytoplasm. | Gaucher's disease |
| Vascular birthmark (port-wine-stain). Benign, but associated with Sturge-Weber syndrome (port wine stain in opthalmic division of trigeminal nerve --> seizures) | Hemangioma |
| Hypoxemia, polycythemia, hypercapnia. Chronic bronchitis (hyperplasia of mucus cells in bronchioli). Increased REID index. | "Blue bloater" |
| Polyostotic fibrous dysplasia, precocious puberty, cafe-au-lait spots, short stature in a young girl. Mosaic G-protein signaling mutation. | McCune-Albright syndrome |
| Restrictive cardiomyopathy (juvenile form: cardiomegaly), exercise intolerance. Lysosomal glucosidase deficiency. | Pompe's desease. |
| Red "currant jelly" sputum | Klebsiella pneumoniae |
| Bilateral hilar adenopathy, uveitis, noncaseating granulomas. | Sarcoidosis |
| Systolic ejection murmur (crescendo-decrescendo) | Aortic valve stenosis |
| Splinter hemorrhages in fingernails (not always) | Bacterial endocarditis |
| Polyuria, acidosis, growth failure, electrolyte imbalances. Proximal tubular (PCT) reabsorption defect. | Fanconi's syndrome |
| "Cherry-red spot" on macula |
Tay-Sachs (ganglioside accumulation) Niemann-Pick (lysosomal storage disorder) Central retinal artery occlusion |
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Chorea, dementia (Crazy), Caudate degeneration, decrease AcH Autosomal Dominant, shows anticipation CAG repeat expansion |
Huntingon's disease |
| Swollen gums, mucous bleeding, poor wound healing, spots on skin. Vitamin C deficiency: can't hydroxylate proline/lysine for collagen synthesis. | Scurvy |
| Green-yellow (oxidized copper) rings around peripheral cornea. Due to copper accumulation from Wilson's disease. | Kayser-Fleischer rings |
| Hypertension, hypokalemia, metabolic acidosis. | Conn's syndrome (primary hyperaldosteronism) |
| Single palm crease | Simian crease (seen in Down's) |
| Lucid interval after traumatic brain injury. "Talk and Die" | Epidural hematoma |
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No lactation post partum, absent menstruation, cold intolerance. Multiple pituitary hormones not working. Post partum hemorrhage --> hypotension --> pituitary infarct -> necrosis --> no hormones. |
Sheehan's syndrome |
| Weight loss, diarrhea, arthritis, fever, adenopathy | Whipple's disease (Tropheryma whippelii) |
| Continuous "machine-like" murmur | PDA (close with indomethacin; open with misoprostol) |
| Pink complexion, dyspnea, hyperventilation. | "Pink puffer" [emphysema: centroacinar (smoking), panacinar (alpha1-antitrypsin deficiency)] |
| Dog or cat bite resulting in infection | Pasturella multocida |
| A 53-year-old man with multilobe bronchopneumonia due to Streptococcus pneumoniae infection appears mildly cyanotic. Arterial blood gas analysis shows a PaO2 of 70 mm Hg and a PaCO2 of 42 mm Hg. Which of the following is the most likely explanation for hy | Option C (multiple ventilation/perfusion units approaching zero, producing a physiologic shunt) is correct. In this patient, many of the infected areas of the pulmonary parenchyma have blood flowing through them, but the alveoli are filled with fluid or purulent exudate that reduces or prohibits ventilation. This effectively acts as a shunt by combining unoxygenated or poorly oxygenated blood with normally oxygenated blood from the unaffected areas of the lung. Therefore, blood leaving the lung has a reduced PaO2. As a general principle, the most common cause of a reduced PaO2 is the presence of low V/Q units. |
| A 53-year-old man with multilobe bronchopneumonia due to Streptococcus pneumoniae infection appears mildly cyanotic. Arterial blood gas analysis shows a PaO2 of 70 mm Hg and a PaCO2 of 42 mm Hg. Which of the following is the most likely explanation for hy |
Option A (edema in many alveoli due to pulmonary infection, preventing adequate gas exchange) is incorrect. This answer addresses only ventilation and does not consider perfusion. The mismatch is between ventilation and perfusion (V/Q ratio). Option B (insufficient ventilation due to pleural pain, preventing adequate oxygenation) is incorrect. Reduced ventilation primarily tends to increase PaCO2, but does not decrease PaO2 until late in the disease process. Option D(serious reduction of blood flow in of the pulmonary circulation due to pulmonary congestion) is incorrect. With normal circulation, red blood cells are completely oxygenated when they have passed about one-third of the distance through an alveolar capillary. Slowing blood flow through the lungs would neither affect the PaO2 nor reduce the ability of the lungs to fully saturate hemoglobin with oxygen. |
| Large rash w/ bull's eye appearance. Associated with tick bite. Lyme disease: Borrelia | Erythema chronicum migrans |
| Calf pseudohypertrophy (excess fatty and connective tissue) | Muscular dystrophy (Duchenne's most commonly) |
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A febrile 22-year-old woman complains of crampy right upper quadrant pain. Physical examination shows scleral icterus, right upper quadrant tenderness to palpation, and mild splenomegaly. Laboratory studies show: Leukocyte count 18,000 Hemoglobin 9.5 g/ |
Option B (increased RBC osmotic fragility) is correct. The patient has congenital spherocytosis complicated by acute cholecystitis secondary to calcium bilirubinate stones. Congenital spherocytosis is an autosomal dominant disease associated with a spectrin defect in the RBC membrane. Spherocytes are easily recognized because they lack central areas of pallor. Normal RBCs are biconcave disks with a central area of pallor where hemoglobin is less concentrated. Splenic macrophages extravascularly remove spherocytes, which results in anemia and an increase in serum levels of unconjugated bilirubin (end product of hemoglobin metabolism in macrophages). Liver conjugation of excessive unconjugated bilirubin supersaturates the bile, predisposing to the formation of jet-black calcium bilirubinate stones in the gallbladder. The RBC osmotic fragility test will confirm spherocytosis; spherocytes hemolyze earlier than normal RBCs when placed in saline solutions ranging from 0.85% to 0.20% in concentration. Splenectomy is the treatment of choice. |
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A febrile 22-year-old woman complains of crampy right upper quadrant pain. Physical examination shows scleral icterus, right upper quadrant tenderness to palpation, and mild splenomegaly. Laboratory studies show: Leukocyte count 18,000 Hemoglobin 9.5 g/ |
Option A (abnormal hemoglobin electrophoresis) is incorrect. The patient does not have a hemoglobinopathy, such as b-thalassemia, where there is an increase in hemoglobins A2 and F, or sickle cell disease, where there is abnormal hemoglobin and sickled RBCs in the peripheral blood. Option C (low serum ferritin) is incorrect. The patient does not have iron deficiency anemia. Unlike the hemolytic anemias, iron deficiency anemia does not have an elevated, corrected (for the degree of anemia) reticulocyte count. An increased reticulocyte count indicates an appropriate bone marrow response (e.g., increased RBC synthesis) to the anemia, which eliminates bone marrow disease (e.g., aplastic anemia) as the cause of the patient's disorder. Iron deficiency anemia is associated with a low corrected reticulocyte count, because iron is necessary for the synthesis of hemoglobin and proper development of RBCs in the bone marrow. Furthermore, in iron deficiency anemia, the RBCs are microcytic and contain less hemoglobin. This results in a low MCV and a decreased MCHC. In spherocytosis, the MCV is normal and the MCHC is increased, the latter due to increased concentration of hemoglobin in the spherocytes. Option D (positive direct Coombs' test) is incorrect. The patient does not have an autoimmune hemolytic anemia. A direct Coombs' test identifies IgG or complement on the surface of RBCs. The patient has a family history of gallbladder disease and anemia, indicating a genetic rather than acquired basis for RBC hemolysis. Option E (positive Heinz body preparation) is incorrect. The patient does not have glucose-6-phosphate dehydrogenase deficiency, which is a sex-linked recessive disease predominantly seen in males. |
| A 69-year-old African-American woman complains of fatigue and pain in her lower back and ribs. She states that she has been having problems with voiding urine for the past few days. Physical examination shows percussion tenderness over the lower vertebrae | Option B (malignant plasma cell disorder) is correct. The patient has multiple myeloma (MM) complicated by renal failure due to precipitation of Bence Jones (BJ) protein (light chains) in the renal tubules. MM is the most common primary malignancy of bone, and is more common in African Americans than in whites. Lytic bone lesions result from secretion of osteoclast-activating factor (interleukin-1) by malignant plasma cells. In >80% of cases, SPE shows a monoclonal spike in the gamma-globulin region. A single clone of malignant plasma cells produces the predominant immunoglobulin (Ig), usually IgG; hence the sharp spike in the gamma-globulin region of SPE. The immunoglobulin's corresponding light chain (kappa or lambda) BJ protein is spilled into the urine. Because urine dipsticks for protein detect only albumin (whereas the SSA detects both albumin and globulins), a disparity between the urine protein dipstick reaction (trace or +1) and SSA (+3 or +4) excludes albumin as the cause of proteinuria and is highly suggestive of BJ protein in the urine. A bone marrow aspirate showing sheets of malignant plasma cells is mandatory to confirm the diagnosis. Serum immunoelectrophoresis identifies the Ig involved. Renal failure is a common cause of death in MM. Note the increase in serum BUN and creatinine levels and renal tubular casts in this patient. |
| A 69-year-old African-American woman complains of fatigue and pain in her lower back and ribs. She states that she has been having problems with voiding urine for the past few days. Physical examination shows percussion tenderness over the lower vertebrae |
Option A (immunoglobulin M-producing lymphoproliferative disorder) is incorrect. An IgM-producing lymphoproliferative disorder is called Waldenstrom's macroglobulinemia. Unlike MM, this malignant disorder is not associated with lytic lesions and acts more like a malignant lymphoma in that it metastasizes to lymph nodes. Option C (malignant T-cell disorder) and Option D (metastatic disease of undetermined origin) are incorrect. Unlike MM, these disorders are not associated with monoclonal spikes or Bence Jones protein. Option E (renal failure of undetermined origin) is incorrect. This patient's renal failure is a complication of MM, rather than a cause of her skeletal and hematologic problems. |
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Meckel's diverticulum is an uncommon congenital malformation that is usually a clinically silent condition. In some cases, Meckel's diverticulum can be confused with appendicitis in the presence of A. heterotopic gastric tissue B. heterotopic pancrea |
Option A (heterotopic gastric tissue) is correct. Meckel's diverticulum is a congenital malformation of the small intestine, and occurs in about 2% of the population. It is uncommon, but not rare. If the diverticulum contains heterotopic gastric mucosa, it may ulcerate and cause significant bleeding. It can produce symptoms similar to appendicitis (e.g., right lower quadrant pain). |
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Meckel's diverticulum is an uncommon congenital malformation that is usually a clinically silent condition. In some cases, Meckel's diverticulum can be confused with appendicitis in the presence of A. heterotopic gastric tissue B. heterotopic pancrea |
Option B (heterotopic pancreatic tissue) is incorrect. The presence of pancreatic tissue would not cause ulceration and bleeding. Option C (obstruction of the small intestine) is incorrect. Obstruction may occur if there is intussusception or incarceration of the diverticulum. Option D (roundworm infestation) is incorrect. Roundworms may cause vague abdominal discomfort. Option E (ulcerative colitis) is incorrect. Ulcerative colitis would not be found in the presence of Meckel's diverticulum. Except for a "wash-through" effect to the terminal ileum, ulcerative colitis is a condition that affects the large bowel only. |
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16. The photomicrograph shows histologic changes in the glomerulus of a 24-year-old man who died in acute renal failure from Goodpasture's syndrome. The arrows in the figure point to which of the following pathologic changes? A. Caseous necrosis B. Co |
Option D (fibrinoid necrosis) is correct. The micrograph shows changes characteristic of fibrinoid necrosis. Much of the staining quality comes from insudation of plasma proteins into the interstitium due to injury of the vascular wall. Fibrinoid necrosis is often seen in hypersensitivity disease as well as in malignant hypertension. |
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16. The photomicrograph shows histologic changes in the glomerulus of a 24-year-old man who died in acute renal failure from Goodpasture's syndrome. The arrows in the figure point to which of the following pathologic changes? A. Caseous necrosis B. Co |
Option A (caseous necrosis), Option B (coagulation necrosis), Option C (fat necrosis), and Option E (liquefaction necrosis) are incorrect. The characteristic features of caseous necrosis, coagulation necrosis, fat necrosis, and liquefaction necrosis are absent. Refer to the discussion for Option D. |
| A 29-year-old Greek medical missionary, who recently returned to the United States after spending 3 months in Africa, is diagnosed with malaria due to Plasmodium vivax. After 4 days of therapy with primaquine, he develops a fever, chills, low back pain, a | Option E (positive Heinz body preparation) is correct. The patient has glucose-6-phosphate dehydrogenase (G6PD) deficiency, a sex-linked recessive disorder. G6PD deficiency leads to decreased synthesis of glutathione (GSH), which is necessary to neutralize peroxide in RBCs. The hemolysis is predominantly intravascular, leading to hemoglobinuria. Infection and therapy with oxidant drugs (e.g., primaquine and dapsone) precipitate hemolysis. In the Mediterranean variant, which is common in individuals of Mediterranean descent, fava beans can precipitate hemolysis. In G6PD deficiency, oxidant damage to RBCs leads to an accumulation of peroxide that cannot be neutralized by GSH. Peroxide damages the RBC membrane (intravascular hemolysis) and denatures hemoglobin, which forms discrete inclusions called Heinz bodies. Splenic macrophages often remove damaged RBC membranes, leaving cells with membrane defects, called "bite cells," circulating in the peripheral blood. The screening test of choice in acute hemolysis is a Heinz body preparation, which requires a special supravital stain to identify the Heinz bodies. Enzyme analysis for G6PD is the confirmatory test and must be performed when active hemolysis has subsided. African Americans have a milder variant of G6PD deficiency. |
| A 29-year-old Greek medical missionary, who recently returned to the United States after spending 3 months in Africa, is diagnosed with malaria due to Plasmodium vivax. After 4 days of therapy with primaquine, he develops a fever, chills, low back pain, a |
Option A (abnormal hemoglobin electrophoresis) is incorrect. The patient does not have an increase in normal hemoglobin (e.g., hemoglobin A2 or F) or the presence of abnormal hemoglobin (e.g., hemoglobin S). Option B (low mean corpuscular hemoglobin concentration) is incorrect. Patients with G6PD deficiency have normal hemoglobin synthesis, hence a normal MCHC. Option C (low serum ferritin concentration) is incorrect. The patient does not have iron deficiency anemia, which is associated with an inadequate reticulocyte response to the anemia. Option D (positive direct Coombs' test) is incorrect. Use of primaquine is not associated with an autoimmune hemolytic anemia. |
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The photomicrograph shows a gonadal neoplasm from an 18-year-old man with a 2-month history of painless testicular enlargement. The neoplasm shows characteristics that would best classify it as A. choriocarcinoma B. embryonal cell carcinoma C. semin |
Option D (teratoma) is correct. The micrograph shows elements derived from all three germ layers, which classifies it as a teratoma. Because all of the elements are mature and no evidence of neoplasia is apparent, this section represents a mature teratoma. |
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The photomicrograph shows a gonadal neoplasm from an 18-year-old man with a 2-month history of painless testicular enlargement. The neoplasm shows characteristics that would best classify it as A. choriocarcinoma B. embryonal cell carcinoma C. semin |
Option A (choriocarcinoma) is incorrect. Choriocarcinomas contain syncytiotrophoblastic differentiation (showing the characteristic multinucleated giant cells) and cytotrophoblastic differentiation. Option B(embryonal cell carcinoma) is incorrect. Embryonal cell carcinomas are composed of nondescript masses of undifferentiated cells growing in a glandular, alveolar, or tubular pattern. Less well differentiated tumors would simply be sheets of cells. Option C (seminoma) is incorrect. Seminomas consist of sheets of large polygonal seminoma cells in an organoid pattern, separated by bands of connective tissue that often contains a dense infiltrate of lymphocytes. Option E (yolk sac tumor) is incorrect. Yolk sac tumors display a lace-like pattern with occasional primitive glomerulus-like Schiller-Duval bodies. |
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A 12-year-old child develops wheezing and dyspnea after petting a cat. The child is suffering from which of the following forms of asthma? A. Allergic bronchopulmonary aspergillosis B. Atopic asthma C. Intrinsic nonreaginic asthma D. Intrinsic pha |
Option B (atopic asthma) is correct. Atopic, or allergic, asthma involves a type I hypersensitivity reaction. The binding of an inhaled specific allergen, such as cat dander, to IgE on the surface of a mast cell induces an attack of typical atopic asthma. |
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A 12-year-old child develops wheezing and dyspnea after petting a cat. The child is suffering from which of the following forms of asthma? A. Allergic bronchopulmonary aspergillosis B. Atopic asthma C. Intrinsic nonreaginic asthma D. Intrinsic pha |
Option A (allergic bronchopulmonary aspergillosis) is incorrect. Colonization of the bronchi by Aspergillus with development of hypersensitivity to the fungus is the cause of allergic bronchopulmonary aspergillosis. Option C (intrinsic nonreaginic asthma). A viral infection, exposure to cold, or inhaled irritants are all associated with intrinsic nonreaginic asthma. The triggering mechanisms are nonimmune. The mechanism is not well understood but thought to be due, at least in part, to unusually reactive airways. Option D(intrinsic pharmacologic asthma) is incorrect. Ingestion of aspirin or a nonsteroidal anti-inflammatory drug generally causes this type of asthma. It is thought that aspirin blocks cyclooxygenase, reducing prostaglandins but not affecting production of leukotrienes. The imbalance causes bronchoconstriction. Option E (occupational asthma) is incorrect. Fumes or inhaled air pollutants usually induce this occupational asthma, which may be mediated by IgG. Often, no specific mechanism can be identified. |
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The photomicrograph shows subserosal connective tissue taken from the appendix of a 7-year-old girl suffering from acute appendicitis with a fibrinopurulent exudate coating the serosal surface. The neutrophils within this venule show evidence of A. apo |
Option D (pavementing) is correct. At the pavementing stage, the neutrophils are tightly adherent to the endothelium and are preparing to pass through it by diapedesis. |
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The photomicrograph shows subserosal connective tissue taken from the appendix of a 7-year-old girl suffering from acute appendicitis with a fibrinopurulent exudate coating the serosal surface. The neutrophils within this venule show evidence of A. apo |
Option A (apoptosis) is incorrect. Many of the neutrophils eventually undergo apoptosis, but at this stage none show characteristic morphologic changes, such as nuclear fragmentation. Option B (diapedesis) is incorrect. None of the cells appear to be passing through the vessel wall, although they will eventually move through the wall. Option C (margination) is incorrect. During margination, the neutrophils move to the periphery of the flowing blood and are not adhering to the endothelium. Option E (rolling) is incorrect. At this stage, the neutrophils are still moving along the vessel, but have begun to adhere to the endothelium. |
| Keratin pearls on skin lesion. | Squamous cell carcinoma (all squamous cell cancers) |
| Necrotizing vasculitis (lungs) and necrotizing glomerulonephritis. Hemoptysis and glomerular disease. | Wegener's (add sinusitis as symptom) and Goodpasture's (Anti-GBM) |
| A 62-year-old woman with bilateral palpable masses in her abdomen has a creatinine level of 3.7 mg/dL and her blood urea nitrogen (BUN) is 32 mg/dL. During the past year, she has had hematuria with occasional small blood clots in her urine. Which of the f | Option C (polycystic kidney disease, autosomal dominant) is correct. This clinical scenario of bilateral palpable abdominal masses and marked increase in creatine and BUN represents a fairly classic presentation of autosomal dominant (adult) polycystic disease. |
| A 62-year-old woman with bilateral palpable masses in her abdomen has a creatinine level of 3.7 mg/dL and her blood urea nitrogen (BUN) is 32 mg/dL. During the past year, she has had hematuria with occasional small blood clots in her urine. Which of the f |
Option A (medullary sponge kidney) is incorrect. In this condition, the kidneys are not particularly enlarged. Option B (nephronophthisis) is incorrect. Kidneys are smaller than normal in a patient with nephronophthisis. Option D (polycystic kidney disease, autosomal recessive) is incorrect. This form of polycystic kidney disease is rare in children. In the perinatal period, it is associated with a mortality of about 75%. Option E (renal dysplasia) is incorrect. Renal dysplasia is the most common cause of a unilateral abdominal mass in newborns. |
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A 61-year-old man with chronic renal failure is being considered for a renal transplant. His serum calcium level is 7.6 mg/dL. Which of the following findings is most likely to be typical in this patient? A. Bilateral adrenal hyperplasia B. Enlargeme |
Option B (enlargement of all four parathyroid glands) is correct. The patient has secondary hyperparathyroidism associated with chronic renal failure. In such cases, the hypocalcemia caused by renal retention of phosphate leads to compensatory hyperplasia of the parathyroid glands. Typically, all four parathyroid glands are enlarged. |
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A 61-year-old man with chronic renal failure is being considered for a renal transplant. His serum calcium level is 7.6 mg/dL. Which of the following findings is most likely to be typical in this patient? A. Bilateral adrenal hyperplasia B. Enlargeme |
Option A (bilateral adrenal hyperplasia), Option D (hyperplasia of the adenohypophysis), and Option E (hyperplasia of the thyroid follicular cells) are incorrect. Chronic renal failure and low serum calcium level would not cause enlargement of the adrenal glands and neither is associated with hyperplasia of the follicular cells of the thyroid. Option C (functional parathyroid adenoma) is incorrect. A functional adenoma would cause the other three parathyroid glands to atrophy, resulting in one large gland (with the adenoma) and three atrophic glands. |
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Individuals taking phenobarbital may be more susceptible to free radical injury by toxins such as carbon tetrachloride (CCl4). Phenobarbital induces which of the following subcellular changes? A. Additional receptor sites for CCl4 on the cell membrane |
Option E (marked hypertrophy of the SER within the hepatocytes) is correct. Phenobarbital induces hypertrophy of the SER and hence a marked increase in cytochrome p450 activity. The conversion of CCl4 into the toxic free radical CCl3 by the cytochrome p450 system causes the injury. |
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Individuals taking phenobarbital may be more susceptible to free radical injury by toxins such as carbon tetrachloride (CCl4). Phenobarbital induces which of the following subcellular changes? A. Additional receptor sites for CCl4 on the cell membrane |
Option A (additional receptor sites for CCl4 on the cell membrane of the hepatocytes) and Option D (increased formation of G proteins within the hepatocytes) are incorrect. Refer to the discussion for option E. Option B (atrophy of the Golgi zone within the hepatocytes) is incorrect. The production of free radicals resulting from CCl4 does not involve the Golgi zone. Option C (atrophy of the smooth endoplasmic reticulum within the hepatocytes). Phenobarbital causes swelling, not shrinking, of the SER. |
| A 22-year-old woman complains of fatigue and frequent nose bleeds. Physical examination shows generalized petechiae and ecchymoses, generalized lymphadenopathy, and hepatosplenomegaly. The peripheral smear shows hypergranular blast cells containing numero | Option C (increases maturation of the blast cells) is correct. The patient has acute promyelocytic (progranulocytic) leukemia (FAB classification M3). Unique characteristics associated with this form of leukemia include a high incidence of disseminated intravascular coagulation, or DIC (which is present in this patient), a t(15;17) translocation, abnormal retinoic acid metabolism, and an excellent response to treatment with retinoic acid, which matures the promyelocytes. |
| A 22-year-old woman complains of fatigue and frequent nose bleeds. Physical examination shows generalized petechiae and ecchymoses, generalized lymphadenopathy, and hepatosplenomegaly. The peripheral smear shows hypergranular blast cells containing numero |
Option A (destroys the blast cells),Option B(enhances cellular immunity), Option D (prevents infection related to bone marrow suppression), and Option E (prevents intravascular coagulation) are incorrect. Substances released from the granules of the promyelocytes activate the coagulation cascade, leading to intravascular coagulation). D-dimers are fibrin monomers found in a fibrin clot that have been cross-linked by factor XIII (fibrin-stabilizing factor). Their presence indicates that intravascular coagulation has occurred. Refer to the discussion for Option C. |
| Several weeks after sustaining a gunshot wound, the bullet is surgically removed from the shoulder of a 20-year-old man. Histologically, the lesion resembles a chronic inflammatory infiltrate, with numerous macrophages surrounding the bullet. In the chron | Option C (involved in the production of numerous biologically active substances) is correct. Macrophages produce an abundance of biologically active substances (e.g., toxic free radicals, proteases, cytokines, growth factors, and angiogenesis factor), and all are involved in chronic inflammation. |
| Several weeks after sustaining a gunshot wound, the bullet is surgically removed from the shoulder of a 20-year-old man. Histologically, the lesion resembles a chronic inflammatory infiltrate, with numerous macrophages surrounding the bullet. In the chron |
Option A (capable of local proliferation) is incorrect. Macrophages can reproduce locally, but this simply increases their number. Option B (easily recruited from the circulation) is incorrect. Macrophages are easily recruited from the circulation by various chemotactic factors recruit easily, but many other inflammatory cells can also be attracted similarly. Option D (permanently localized to the site of inflammation) is incorrect. Although some cytokines can immobilize macrophages and are retained in the area of inflammation, this only tends to increase their number. |
| A 22-year-old medical student volunteers for a hematology research project and is found to be lacking one of four a-globin genes. Previously, he had several hematologic studies that were within normal limits. The significance of this unexpected finding su | Option D (is an asymptomatic carrier of a-thalassemia) is correct. Deletion of one of the four a-globin genes produces a silent carrier state, and no hematologic abnormalities are evident. One of the chromosome 16 genes carries this deficiency. If such an individual has offspring with another carrier, the children could have the a-thalassemia trait. There are four functional a-globin genes; thus, there are four possible degrees of a-thalassemia (based on the loss or one to four genes). This individual has the mildest form; the most severe form is associated with fetal death in utero. |
| A 22-year-old medical student volunteers for a hematology research project and is found to be lacking one of four a-globin genes. Previously, he had several hematologic studies that were within normal limits. The significance of this unexpected finding su |
Option A (has a moderate degree of erythroid hyperplasia in bone marrow), Option B (has an abnormal hemoglobin concentration), Option C (has numerous target cells in the peripheral blood), and Option E (may develop severe hemolytic anemia if exposed to oxidant drugs) are incorrect. Loss of one a-globin allele is silent and results in no hematologic abnormalities, such as hemoglobin Bart's. Sensitivity to oxidant drugs (e.g., antimalarials, sulfonamides, nitrofurantoin, phenacetin, aspirin in large doses, vitamin K derivatives) is associated with glucose-6-phosphate dehydrogenase deficiency, not with a-thalassemia. |
| A 35-year-old pharmacist complains of recurrent episodes of forgetfulness and tiredness. Physical examination is essentially unremarkable. Laboratory studies show a serum glucose level of 20 mg/dL. Additional studies on the same serum sample show a high s | Option D (surreptitiously injected human insulin) is correct. Normally, b-islet cells first synthesize preproinsulin in the rough endoplasmic reticulin. Preproinsulin then is delivered to the Golgi apparatus, where proteolytic reactions generate insulin and a cleavage peptide called C peptide. Hence, C peptide is a marker for endogenous synthesis of insulin. In this case, the patient has been injecting himself with insulin. This increases the serum insulin level; however, serum C peptide is decreased due to suppression of the b-islet cells by the exogenously administered insulin. |
| A 35-year-old pharmacist complains of recurrent episodes of forgetfulness and tiredness. Physical examination is essentially unremarkable. Laboratory studies show a serum glucose level of 20 mg/dL. Additional studies on the same serum sample show a high s |
Option A (benign tumor involving b-islet cells in the pancreas) is incorrect. Insulinomas are benign tumors of the b-islet cells that synthesize excess insulin, resulting in severe fasting hypoglycemia. As expected, these patients have increased serum insulin and C-peptide levels, indicating that b -islet cells are synthesizing the insulin. Option B (ectopic secretion of an insulinlike factor) is incorrect. This lowers both the serum insulin and the C-peptide levels due to hypoglycemia suppressing the b-islet cells from synthesizing insulin. b-islet cells in the pancreas) is incorrect. This describes a glucagonoma, which produces hyperglycemia by stimulating gluconeogenesis. |
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19. The photomicrograph shows a section from the wall of a 15-cm, multiloculated cystic lesion found on the right ovary of a 37-year-old woman. The left ovary was free of any gross abnormality. The neoplasm would most likely be classified as A. arrheno |
Option D (mucinous cystadenoma) is correct. The uniform simple mucin-producing epithelium confirms the diagnosis of mucinous cystadenoma. There is no microscopic atypia, and in the gross description, there is no mention of areas of papillary change or solid areas. |
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19. The photomicrograph shows a section from the wall of a 15-cm, multiloculated cystic lesion found on the right ovary of a 37-year-old woman. The left ovary was free of any gross abnormality. The neoplasm would most likely be classified as A. arrheno |
Option A (arrhenoblastoma), Option B (dysgerminoma), Option C (endodermal sinus tumor), and Option E (serous cystadenoma) are incorrect. Arrhenoblastomas and dysgerminomas are solid tumors and would not be expected to be large and cystic. Endodermal sinus tumors would be very atypical and form a lace-like pattern with occasional Schiller-Duval bodies.The lining epithelium of serous cystadenomas is not mucin-producing. |
| Red urine in the morning. Hb breakdown b/c complement is attacking RBC's b/c they have a deficiency of CD55/CD59. | Paroxysmal nocturnal hemoglobinuria (PNH) |
| A 63-year-old man has a history of congestive heart failure due to severe arteriosclerosis of the coronary arteries. He now has pitting edema of the ankles that extends about halfway up the lower part of his legs. The edema in this patient is most likely | Option C (increased hydrostatic pressure in the vascular compartment) is correct. In this patient, the increased pressure is the main cause of dependent edema. The failing right side of the heart (right atrium and ventricle) has led to an increase in intravascular hydrostatic pressure, which eventually causes a net movement of fluid from the vascular space to the extravascular space. |
| A 63-year-old man has a history of congestive heart failure due to severe arteriosclerosis of the coronary arteries. He now has pitting edema of the ankles that extends about halfway up the lower part of his legs. The edema in this patient is most likely |
Option A (decreased oncotic pressure in the vascular compartment) is incorrect. In some renal diseases, such as minimal change disease, reduced oncotic pressure due to the loss or lack of synthesis of albumin is the mechanism for the development of generalized massive edema (anasarca). Option B (impaired lymphatic drainage of the legs) is incorrect. This condition can certainly cause edema, but pathology causing the lymphatic obstruction should be evident. Option D (increased oncotic pressure in the extracellular compartment) is incorrect. An increase in oncotic pressure in the vascular compartment would tend to draw in fluid from the extravascular space, rather than move it into the extravascular space. Option E (increased vascular permeability) is incorrect. In inflammatory conditions, increased vascular permeability is the mechanism for the development of edema. |
| A patient has vague symptoms of weakness and fatigue and decreased exercise tolerance. Laboratory studies show a leukocyte count of 11,000/mm with 7% blasts on the peripheral smear. Bone marrow aspirate shows 40% myeloblasts. Acute myeloblastic leukemia i | Option D is correct. Acute myeloblastic leukemia (AML) is primarily a disease of young adults. |
| A patient has vague symptoms of weakness and fatigue and decreased exercise tolerance. Laboratory studies show a leukocyte count of 11,000/mm with 7% blasts on the peripheral smear. Bone marrow aspirate shows 40% myeloblasts. Acute myeloblastic leukemia i | Option A (birth to 2 years) Option B (2-10 years) Option c (10-15 years), and Option E (>40 years) are incorrect. A young age is more consistent with acute lymphoblastic leukemia (ALL). Acute myeloblastic leukemia (AML) accounts for only 20% of childhood leukemias. Individuals who are more than 40 years of age are more liable to develop chronic myeloid leukemia (CML). |
| A 69-year-old man sees his physician because of increasing shortness of breath. X-ray film of the chest shows that most of the right lung is encased by a thick layer of moderately dense tissue. Pleural fluid is blood-tinged with numerous atypical cells. T | Option A (asbestos) is correct. About 90% of malignant mesotheliomas are related to occupational exposure to asbestos. Individuals who have been exposed to asbestos have an 8% risk of developing malignant mesothelioma. There is a long latent period, with the tumor appearing from about 20-40 years after exposure to the substance. |
| A 69-year-old man sees his physician because of increasing shortness of breath. X-ray film of the chest shows that most of the right lung is encased by a thick layer of moderately dense tissue. Pleural fluid is blood-tinged with numerous atypical cells. T |
Option B (formalin) is incorrect. Formalin has been attributed to a number of untoward effects; however, pathologists have received extensive exposure to formalin for many years without a strong association with any conditions, except rare hypersensitivity reactions. Formalin has no association with malignant mesothelioma. Option C (hematite) is incorrect. Exposure to hematite dust may cause siderosis of the lung and perhaps fibrosis. Option D (nickel carbonyl) is incorrect. Nickel carbonyl is associated with development of squamous cell carcinoma of the paranasal sinuses and lung. Option E (silica) is incorrect. Silica exposure is associated with pulmonary fibrosis. |
| A 63-year-old woman with a history of type 2 diabetes mellitus and an increasing exercise limitation is admitted to the hospital with severe influenza pneumonitis. She subsequently develops adult respiratory distress syndrome (ARDS) and dies 4 days after | Option C (idiopathic) is correct. A well-defined history of a previous suppurative, hemorrhagic, or caseous pericarditis is often absent in the patient who dies of constrictive pericarditis. |
| A 63-year-old woman with a history of type 2 diabetes mellitus and an increasing exercise limitation is admitted to the hospital with severe influenza pneumonitis. She subsequently develops adult respiratory distress syndrome (ARDS) and dies 4 days after |
Option A (cryptococcosis) is incorrect. Cryptococcus,a yeast-like pathogen, usually causes a mild pulmonary infection. Cryptococcosis is not a major cause of pericarditis, but it may lead to meningitis. Option B (histoplasmosis) is incorrect. Although histoplasmosis can cause constrictive pericarditis, it is not the most common cause of this disorder. Option D (oat cell carcinoma) is incorrect. Oat cell carcinoma can involve the pericardium, but its effects are acute, with formation of a bloody effusion rather than scar tissue. Option E (tuberculosis) is incorrect. Although tuberculosis once was an important cause of constrictive pericarditis, this pulmonary disorder is no longer the most common cause. |
| An ultrasound examination of a 17-year-old boy with a firm, enlarged right testicle shows a 1-cm cyst. Examination of the testicle after orchiectomy shows a cystic lesion filled with a somewhat cheese-like appearing component that is separated from otherw | Option C (germ cell tumor with undetermined malignant potential) is correct. The presence of skin-like tissue in the tumor would determine that the lesion is a mature teratoma, a mass that contains fully differentiated tissue from one or more germ cell layers (e.g., epithelium). Unlike dermoid cysts in the ovary, mature teratomas in the testis are not always benign and have a potential to become malignant; thus, they cannot be considered totally benign. Small foci of undetected malignant components are possible |
| An ultrasound examination of a 17-year-old boy with a firm, enlarged right testicle shows a 1-cm cyst. Examination of the testicle after orchiectomy shows a cystic lesion filled with a somewhat cheese-like appearing component that is separated from otherw | Option A (benign germ cell tumor), Option B (benign stromal cell tumor), and Option D (inclusion cyst derived from the overlying scrotal skin) are incorrect. Teratomas are germ cell tumors that form elements of one or more germ cell layers. Inclusion cysts of the skin are attached to the skin, but do not invade the testis. |
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The mechanism thought to be responsible for the increasingly aggressive behavior of malignant tumors is that they A. are genetically labile B. cause the production of tumor necrosis factor-a (TNF-a) C. induce angiogenesis D. produce paraneoplasti |
Option A (are genetically labile) is correct. Malignant tumors are constantly mutating and forming new clones. Many of the clones die, but some will have a selective advantage with regard to growth, invasion, or metastasis. |
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The mechanism thought to be responsible for the increasingly aggressive behavior of malignant tumors is that they A. are genetically labile B. cause the production of tumor necrosis factor-a (TNF-a) C. induce angiogenesis D. produce paraneoplasti |
Option B (cause the production of tumor necrosis factor-a is incorrect. Although malignant tumors do cause macrophages to produce TNF-a, it is believed that this causes cachexia. Option C (induce angiogenesis) is incorrect. Malignant tumors do induce angiogenesis. This allows them to grow larger than about 1 mm (the size limit if they did not develop a blood supply). However, it does not change their potential to become malignant. Option D (produce paraneoplastic syndromes) is incorrect. Malignant tumors may secrete hormones or hormone-like substances that will produce a paraneoplastic syndrome. This capability does not affect the malignant potential of the tumor itself. |
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An 18-year-old man with xeroderma pigmentosum would be particularly susceptible to the development of which of the following tumors? A. Carcinoma of the esophagus B. Carcinoma of the colon C. Carcinoma of the thyroid D. Squamous cell carcinoma of |
Option D (squamous cell carcinoma of the skin) is correct. Xeroderma pigmentosum is an autosomal recessive disease characterized by an inability to repair DNA damage caused by exposure to ultraviolet (UV) light. UV light causes cross-linking of pyrimidine residues, thus preventing normal DNA replication. Such abnormal DNA is repaired by the nucleotide exclusion repair system, and the genes that are normally responsible for this repair mechanism are missing or mutated. Individuals with this disorder subsequently develop tumors related to excessive exposure to the sun, such as squamous cell carcinoma or basal cell carcinoma, at a much earlier age than would be expected. Normally, these tumors are seen after the age of 40 years, depending on amount of sun exposure and genetic factors. Xeroderma pigmentosum occurs less frequently in blacks due to the absorption of UV light and because the melanin in their skin is very protective. |
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An 18-year-old man with xeroderma pigmentosum would be particularly susceptible to the development of which of the following tumors? A. Carcinoma of the esophagus B. Carcinoma of the colon C. Carcinoma of the thyroid D. Squamous cell carcinoma of |
Option A (carcinoma of the esophagus), Option B (carcinoma of the colon), Option C (carcinoma of the thyroid), and Option E (transitional cell carcinoma of the bladder) are incorrect. UV damage makes no contribution to the pathogenesis of these tumors, so xeroderma pigmentosum plays no etiologic role. |
| A 36-year-old man has generalized lymphadenopathy. A histologic examination of a lymph node shows a marked degree of follicular hyperplasia. Which of the following findings would best determine that this condition is a benign reactive process rather than | Option A (polyclonality on DNA hybridization studies) is correct. Polyclonality is a sign of a benign process. Lymphoma is the result of monoclonal expansion of a single cell that has become malignant. |
| A 36-year-old man has generalized lymphadenopathy. A histologic examination of a lymph node shows a marked degree of follicular hyperplasia. Which of the following findings would best determine that this condition is a benign reactive process rather than |
Option B (presence of broad increase in IgG on high-resolution electrophoresis) is incorrect. This benign process is too nonspecific to be reliable. If the lymphoma does not produce immunoglobulin, this result has no diagnostic value. Option C (presence of surface IgG on the cell membrane of the proliferating cells) is incorrect. Surface immunoglobulin is a B cell marker. Option D (presence of translocation t (14;18)(q32;q21)) is incorrect. This translocation is found in most cases of follicular lymphoma. |
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The liver shown in the figure was removed from a 61-year-old woman at autopsy. Both kidneys showed similar changes, and a berry aneurysm was found in the circle of Willis. The changes are most consistent with which of the following disorders? A. Adult |
Option A (adult polycystic kidney disease) is correct. Adult polycystic kidney disease is an autosomal dominant disorder, characterized by massive enlargement of the kidneys, cysts in the liver, and frequently with aneurisms of the circle of Willis. Many patients with adult polycystic kidney disease also have cystic disease of the liver, as shown in the figure. |
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The liver shown in the figure was removed from a 61-year-old woman at autopsy. Both kidneys showed similar changes, and a berry aneurysm was found in the circle of Willis. The changes are most consistent with which of the following disorders? A. Adult |
Option B (familial juvenile nephrophthisis), Option C (infantile polycystic kidney disease), Option D (medullary cystic disease), and Option E (medullary sponge kidney) are incorrect. Liver cysts and cerebral aneurysms are not expected findings in these diseases. |
| An autopsy performed on a 40-year-old man with dementia shows atrophy of the frontal and temporoparietal lobes of the brain. Histologic examination shows senile plaques. The pathogenesis of the dementia in this patient is most closely related to which of | Option A (b-amyloid protein) is correct. Senile plaques are characteristic of Alzheimer's disease (AD), which is the most common cause of dementia in patients over 65 years of age. Senile plaques contain a core of A-b-amyloid surrounded by neurites. The explanation for the age disparity in this case is that the patient has Down syndrome with three functioning chromosome number 21 (e.g., trisomy 21). Chromosome 21 codes for an Alzheimer precursor protein (APP), part of which is amyloid-b (A- b) protein. This protein is toxic to neurons; hence the extra chromosome 21 codes for more of the protein, which results in AD at an early age. |
| An autopsy performed on a 40-year-old man with dementia shows atrophy of the frontal and temporoparietal lobes of the brain. Histologic examination shows senile plaques. The pathogenesis of the dementia in this patient is most closely related to which of |
Option B (decreased dopamine levels) is incorrect. This describes Parkinson's disease, where there is degeneration and depigmentation of neurons in the substantia nigra and locus ceruleus and a corresponding decrease in the synthesis of the neurotransmitter dopamine. Patients have extrapyramidal signs and symptoms and occasionally develop dementia. Option C (slow virus disease) is incorrect. Slow virus diseases include subacute sclerosing panencephalitis (associated with measles), progressive multifocal leukoencephalopathy (associated with papovavirus), and Creutzfeldt-Jakob disease (associated with prions). Although all of these diseases produce dementia, senile plaques are not present in the brain tissue. Option D (triplet repeat mutation) is incorrect. A triplet repeat mutation associated with dementia is Huntington's disease, which is an autosomal dominant disease with triplet repeats of CAG on the short arm of chromosome 4. Atrophy and loss of striatal neurons occur in the caudate nucleus, putamen, and frontal cortex; however, there are no senile plaques in the tissue. Furthermore, patients have chorea and extrapyramidal signs, which are not seen in AD. |
| A 42-year-old woman complains of chronic constipation and progressive weight gain over the past 6 months despite maintaining a pure vegan diet. She takes no prescription or over-the-counter medications. Physical examination shows a pale woman with brittle | Option B (low T4; high TSH; normaln131I) is correct. The patient has primary hypothyroidism, most likely secondary to Hashimoto's thyroiditis. Hashimoto's thyroiditis is an autoimmune thyroiditis with an increase in antimicrosomal and thyroglobulin antibodies. Along with autoimmune destruction of the gland, an autoantibody directed against the TSH receptor inhibits the gland from synthesizing thyroid hormone. The patient exhibits all of the classic signs of hypothyroidism\: brittle hair, periorbital puffiness, delayed deep tendon reflexes, and primary myopathy of the proximal muscles of the thigh (note the increase in serum creatine kinase). As expected, serum T4 levels are decreased because the gland is being destroyed, and serum TSH is increased due to loss of the negative feedback of T |
| A 42-year-old woman complains of chronic constipation and progressive weight gain over the past 6 months despite maintaining a pure vegan diet. She takes no prescription or over-the-counter medications. Physical examination shows a pale woman with brittle |
Option A (low T4; low TSH; low 131 I) is incorrect. These findings are most consistent with secondary hypothyroidism, usually due to hypopituitarism. In children, a craniopharyngioma is the most common cause of hypopituitarism; in adults, a nonfunctioning pituitary adenoma is usually responsible for this condition. Option C (high T4; low TSH; low 131I) is incorrect. These findings are most consistent with a patient whose hyperthyroidism developed from taking an excess amount of thyroid hormone, usually for weight loss. In these patients, the thyroid gland is suppressed and nonpalpable, unlike a gland that produces excessive thyroid hormone. The 131I is decreased, because the gland is inactive and not capable of increasing the uptake of iodine to synthesize thyroid hormone. Option D (high T4; low TSH; high 131 I) is incorrect. These findings are consistent with Graves' disease, which is the most common cause of hyperthyroidism. These patients have an autoantibody against the TSH receptor that increases the synthesis of thyroid hormone. Exophthalmos and pretibial myxedema are unique to the disease. Unlike hyperthyroidism due to exogenous intake of excess thyroid hormone, in Graves' disease, the 131I uptake is high, because the gland requires iodine to synthesize T4 and is diffusely enlarged. |
| An 84-year-old man complains of lower back pain and inability to void urine over the past 24 hours. Physical examination shows point tenderness over the lower lumbar vertebrae and an enlarged bladder extending to the level of the umbilicus. The physician | Option A (digital rectal examination) is correct. Prostate cancer is the most common cancer in men. Point tenderness over the vertebral bodies in an elderly patient is highly suggestive of metastatic prostate cancer, especially coupled with clinical evidence of urinary retention. Because prostate cancers develop in the peripheral zone of the prostate, they are palpated easily by digital rectal examination, especially if they have already spread beyond the gland. |
| An 84-year-old man complains of lower back pain and inability to void urine over the past 24 hours. Physical examination shows point tenderness over the lower lumbar vertebrae and an enlarged bladder extending to the level of the umbilicus. The physician |
Option B (prostate specific antigen) is incorrect. Although a serum PSA test is always part of the work-up of prostate cancer, a digital rectal examination is accomplished in a few minutes and provides immediate information. Furthermore, PSA is not 100% specific for prostate cancer, because the level is also increased in benign prostatic hyperplasia (BPH). In the absence of vertebral body tenderness in this patient, BPH would have been the most likely cause of urinary retention. BPH develops in the periurethral zone of the gland; hence enlargement is more likely to cause obstructive uropathy than prostate cancer. Urinary retention secondary to prostate cancer can occur when disease has invaded the bladder neck and obstructed the ureters. Unlike prostatic acid phosphatase, a rectal examination does not falsely increase serum PSA levels. Option C (radionuclide bone scan) is incorrect. A radionuclide bone scan would be essential for identifying bone metastasis in this patient, however, osteoarthritis and lumbar strain can mimic metastatic cancer to bone. Option D(serum alkaline phosphatase) is incorrect. Prostate cancer is the most common cause of osteoblastic metastases in men. An osteoblastic response in bone results in increased bone density and increased serum alkaline phosphatase. An increased serum alkaline phosphatase lacks specificity, however, because it is also elevated in osteoarthritis (due to reactive bone formation) and cholestatic and metastatic liver disease (due to increased synthesis by bile duct epithelium). Option E (transrectal ultrasound with biopsy) is incorrect. This is the confirmatory test for prostate cancer, not the initial screening test. |
| A 30-year-old woman states that she often burns her hands without feeling any pain. Physical examination shows decreased pain and temperature sensation in the upper extremities, atrophy of the intrinsic muscles of the hands, and abnormal deep tendon refle | Option B (fluid-filled cavity in the cervical spinal cord) is correct. The patient has syringomyelia, the development of an expanding fluid-filled cavity in the cervical spinal cord. This results in destruction of the crossed lateral spinothalamic tracts (loss of pain and temperature sensation), anterior horn cells (loss of the intrinsic muscles of the hand), and other tracts as the cavity expands. It is often confused with amyotrophic lateral sclerosis (ALS); however, in ALS there are no sensory abnormalities. |
| A 30-year-old woman states that she often burns her hands without feeling any pain. Physical examination shows decreased pain and temperature sensation in the upper extremities, atrophy of the intrinsic muscles of the hands, and abnormal deep tendon refle |
Option A (autoimmune destruction of myelin) is incorrect. Multiple sclerosis (MS) is the most common demyelinating disease. Symptoms of MS include blurry vision (optic neuritis), intention tremors, nystagmus, ataxia, and scanning speech. Option C (superoxide free radical destruction of upper and lower motor neurons) is incorrect. This describes the pathogenesis of some cases of ALS where there is a defect in superoxide dismutase on chromosome 21, leading to superoxide free radical damage of upper and lower motor neurons. Option D (tumor in the cervical spinal cord) is incorrect. Although a cervical spinal cord tumor potentially could produce the neurologic findings seen in this patient, the sequence of neurologic defects is more compatible with syringomyelia. Option E (vitamin B12 deficiency) is incorrect. Vitamin B12 deficiency is associated with subacute combined degeneration of the spinal cord. The posterior columns and lateral corticospinal tracts are demyelinated, leading to loss of proprioception (posterior column disease) and upper motor neuron signs and symptoms (lateral corticospinal tract). |
| A 38-year-old woman with chronic liver disease complains of involuntary, flinging movements of her limbs. She states that other members of her family have had chronic liver disease, dementia, and abnormal body movements. Physical examination shows greenis | Option A (decreased serum ceruloplasmin) is correct. The patient has Wilson's disease (hepatolenticular degeneration), which is inherited as an autosomal recessive trait. The disease is characterized by a defect in the elimination of copper in bile. Copper accumulates in the liver, producing toxic damage to the hepatocytes, starting as acute hepatitis and progressing to chronic hepatitis and cirrhosis. Serum copper levels reflect the amount of copper bound to ceruloplasmin (90-95% of the total serum copper level) plus free and unbound copper. As expected in any chronic liver disease, protein synthesis is decreased, including synthesis of ceruloplasmin. Hence, the decrease in ceruloplasmin leads to a decrease in the total serum copper level, with a corresponding increase in the circulating level of free copper. The excess copper accumulates in Descemet's membrane of the eyes, producing the Kayser-Fleischer ring. In the brain, copper produces toxic injury in the basal ganglia, particularly in the putamen, where it causes atrophy and visible cavitation. When toxic injury occurs in the subthalamic nucleus, the patient develops hemiballismus (flailing of the limbs). Extrapyramidal signs and dementia also may occur. |
| A 38-year-old woman with chronic liver disease complains of involuntary, flinging movements of her limbs. She states that other members of her family have had chronic liver disease, dementia, and abnormal body movements. Physical examination shows greenis |
Option B (increased percent iron saturation) is incorrect. This implies the presence of acquired iron overload disease (hemosiderosis) or hemochromatosis, which is an autosomal recessive disorder. Diseases caused by iron overload are not associated with pigment deposits in the eyes, dementia, or movement disorders. Option C (increased total iron-binding capacity) is incorrect. This reflects increased synthesis of transferrin in the liver, which primarily occurs in iron deficiency anemia. In chronic liver disease, the total iron-binding capacity is decreased due to decreased synthesis of transferring. Option D (increased total serum copper) is incorrect. The serum ceruloplasmin is decreased in patients with Wilson's disease; total serum copper level is decreased, and the free copper level is increased in serum and urine. Total copper levels are increased in the liver parenchyma. |
| A 72-year-old man complains of sudden onset of left flank pain and dizziness when he stands up quickly. When he is lying down, his blood pressure is 100/80 mm Hg, and his pulse is 110/min. When he is moved to a sitting position, his blood pressure is 80/6 | Option E (severe atherosclerosis) is correct. The patient has the classic triad of a ruptured abdominal aortic aneurysm: sudden onset of left flank pain, hypotension, and a pulsatile abdominal mass. Atherosclerotic damage of the abdominal aorta weakens the vessel wall, leading to outpouching of the aorta and the potential for rupture as the expansion increases wall stress. |
| A 72-year-old man complains of sudden onset of left flank pain and dizziness when he stands up quickly. When he is lying down, his blood pressure is 100/80 mm Hg, and his pulse is 110/min. When he is moved to a sitting position, his blood pressure is 80/6 |
Option A (genetic defect in collagen) is incorrect. Ehlers-Danlos syndrome has multiple inheritance patterns and is characterized by defects in synthesis and structure of collagen. Clinical abnormalities include hyperextensibility, vascular instability, and a predisposition for dissecting aortic aneurysms, the most common cause of death in these patients. Dissecting aortic aneurysms usually are associated with a sudden onset of chest pain radiating into the back. Those extending distally are less likely to rupture than those extending proximally. This patient does not have Ehlers-Danlos syndrome. Option B (genetic defect in fibrillin) is incorrect. Marfan's syndrome has an autosomal dominant inheritance, and is associated with a defect on chromosome 15 involving the synthesis of a fibrillin component in elastic tissue. Eunuchoid proportions, lens dislocation, arachnodactyly, mitral valve prolapse, and a propensity for dissecting aortic aneurysms are common in these patients. Elastic tissue fragmentation and cystic medial necrosis occur in the wall of the aorta, leading to structural weakness of the vessel. An intimal tear allows blood to dissect through the weak areas. As discussed under Option A, the clinical findings in this patient do not support the diagnosis of a dissecting aortic aneurysm or of Marfan's syndrome. Option C (immunocomplex-mediated disease) is incorrect. Immunocomplex types of vasculitis are more often associated with small vessel vasculitis involving venules, arterioles, or with capillaries and vasculitis involving muscular arteries (e.g., coronary arteries) rather than elastic arteries such as the aorta. Option D (normal changes associated with aging) is incorrect. The aorta is not structurally weakened in older age; it becomes less distensible, but is not prone to rupture. |
| A febrile 68-year-old woman with a 40-year history of smoking cigarettes complains of fatigue and weight loss. Physical examination shows generalized nontender lymphadenopathy, hepatosplenomegaly, and petechiae and ecchymoses scattered over the entire bod | Option A (B-cell malignancy arising from the bone marrow) is correct. The patient has chronic lymphocytic leukemia (CLL). CLL is the most common leukemia; in patients 60 years of age, it is the most common leukemia and the most common cause of generalized lymphadenopathy. Like all leukemias, it arises from stem cells in the bone marrow and can metastasize throughout the body, typically to the lymph nodes, liver, and spleen. Because the B cells are neoplastic, they cannot be antigenically stimulated to produce plasma cells; hence the high incidence of hypogammaglobulinemia and infection in CLL patients. |
| A febrile 68-year-old woman with a 40-year history of smoking cigarettes complains of fatigue and weight loss. Physical examination shows generalized nontender lymphadenopathy, hepatosplenomegaly, and petechiae and ecchymoses scattered over the entire bod |
Option B (hypogammaglobulinemia related to sepsis) is incorrect. In this patient, hypogammaglobulinemia did not produce this patient's hematologic condition, however, it is most likely responsible for her sepsis. Option C (lymphoid leukemoid reaction secondary to sepsis) is incorrect. The patient does not have an exaggerated, benign proliferation of lymphocytes (leukemoid reaction) in response to an infection. In patients with sepsis, expected findings do not include hepatosplenomegaly, generalized nontender lymphadenopathy, lymphocytosis, and hypogammaglobulinemia. These patients have tender lymphadenopathy and neutrophilic leukocytosis. Option D (metastatic lung cancer associated with smoking cigarettes) is incorrect. Although smoking has been implicated in causing leukemia, the clinical and laboratory findings in this patient are totally inconsistent with metastatic lung cancer. Option E (T-cell malignancy arising from lymph nodes) is incorrect. T-cell leukemias are uncommon, usually metastasize to skin, have lytic lesions in bone, and are not associated with hypogammaglobulinemia. |
| During a routine physical examination and urinalysis, microscopic hematuria is detected in the urine of an asymptomatic 21-year-old man. The hematuria resolves within 10 days, but recurs 1 month later. A needle biopsy of the right kidney shows mesangial h | Option E (up to 50% of patients who have this condition eventually require a kidney transplant) is correct. The patient has IgA nephropathy, or Berger's disease. Recurring hematuria, deposits of IgA scattered throughout the mesangial area, and mesangial hypercellularity are all characteristics of Berger's disease. |
| During a routine physical examination and urinalysis, microscopic hematuria is detected in the urine of an asymptomatic 21-year-old man. The hematuria resolves within 10 days, but recurs 1 month later. A needle biopsy of the right kidney shows mesangial h |
Option A (deposits of IgA are monoclonal and suggest a malignancy in lymphoid organs) is incorrect. Instead, the deposits of IgA are polyclonal and probably represent trapped immune complexes. Option B (glomerular damage will proceed at a fast pace, leading to renal failure within 1 year) is incorrect. This form of IgA nephropathy, or Berger's disease, is a slowly progressive condition that causes chronic renal failure over a period of about 20 years. Option C (IgA is directed against components of the glomerular basement membrane) is incorrect. In IgA nephropathy, known as Berger's disease, there is no suggestion that the IgA is directed against any particular glomerular structure. Evidence suggests that Berger's disease is an immune complex condition. Option D (the condition is acute and self-limited) is incorrect. Chronic renal failure does not ultimately develop in all patients with Berger's disease (an IgA nephropathy), but the condition tends to recur every few months. |
| A 58-year-old man who has smoked 2 packs of cigarettes daily for 30 years has a chronic cough and occasionally produces blood-tinged sputum. X-ray film of the posteroanterior chest shows a mass in the region of the hilum of the left lung. His serum calciu | Option E(squamous cell carcinoma) is correct. Any histologic type of neoplasm may produce any of the paraneoplastic syndromes associated with lung cancer, but squamous cell carcinoma is most often associated with hypercalcemia. |
| A 58-year-old man who has smoked 2 packs of cigarettes daily for 30 years has a chronic cough and occasionally produces blood-tinged sputum. X-ray film of the posteroanterior chest shows a mass in the region of the hilum of the left lung. His serum calciu |
Option A (adenocarcinoma) and Option C (bronchioloalveolar cell carcinoma) are incorrect. Adenocarcinoma or bronchioalveolar cell carcinoma may occasionally produce any of the paraneoplastic syndromes associated with carcinoma of the lung, but they are not associated with hypercalcemia. Option B (bronchial carcinoid tumor) is incorrect. A bronchial carcinoid tumor is rarely associated with the production of a paraneoplastic syndrome. Option D (small cell carcinoma) is incorrect. Small cell (or oat cell) carcinomas are more likely to be associated with secretion of antidiuretic hormone or adrenocorticotropic hormone. |
| A 62-year-old man has smoked two packs of cigarettes a day for 30 years. He states that almost every morning during this time, he has coughed up a tablespoon or more of yellow-green sputum. Physical examination shows cyanosis of the skin and mucous membra | Option B (decreased arterial pH; increased arterial PCO 2; increased serum HCO3) is correct. The patient has chronic obstructive pulmonary disease (COPD) with cyanosis secondary to hypoxemia (decreased arterial PO2). Chronic bronchitis is the primary type of COPD in a patient who has had a productive cough for the majority of the time he has smoked. Obstruction to airflow secondary to inflammation and increased mucus production is at the level of the terminal bronchioles. Therefore, during expiration, air with high concentrations of CO2 is trapped behind the obstruction. Retention of CO2 in the alveoli increases the arterial PCO2, causing respiratory acidosis. Point B on the graph depicts an acid arterial pH, a PCO2 close to the 60 mm Hg isobar, and an HCO level above the normal of 24 mEq/L. Because the patient has had COPD for most of his life, there has been ample time for the kidneys to reclaim and synthesize HCO, producing metabolic alkalosis to compensate for the respiratory acidosis. Compensation for all acid-base disorders brings the pH close to, but not into, the normal range for arterial pH. This describes a partially compensated acid-base condition. Full compensation rarely occurs because it implies that the arterial pH is brought back into the normal range. The absence of compensation indicates that there has not been enough time for the lungs to compensate for primary metabolic conditions or for the kidneys to compensate for primary respiratory conditions. |
| A 62-year-old man has smoked two packs of cigarettes a day for 30 years. He states that almost every morning during this time, he has coughed up a tablespoon or more of yellow-green sputum. Physical examination shows cyanosis of the skin and mucous membra |
Option A (decreased arterial pH; increased arterial PCO2 ; increased serum HCO) is incorrect. These findings are most consistent with a partially compensated acute respiratory acidosis. When compared with Option B (a patient with chronic respiratory acidosis), the lack of adequate compensation has done little to raise the arterial pH. Examples of acute respiratory acidosis include depression of the medullary respiratory center (e.g., patient taking barbiturates); paralysis of the muscles of respiration (e.g., polio, Guillain-Barr\'e9 syndrome); and severe pneumonia. Option C (increased arterial pH; increased arterial PCO2; increased serum HCO) is incorrect. These findings are most consistent with a partially compensated primary metabolic alkalosis (compensation is respiratory acidosis). Examples include diuretics (patient taking primarily loop diuretics and thiazides), vomiting, and mineralocorticoid excess (e.g., primary aldosteronism). Option D (decreased arterial pH; decreased arterial PCO2; decreased serum HCO) is incorrect. These findings are most consistent with a partially compensated primary metabolic acidosis (respiratory alkalosis is compensation). Examples include renal failure, lactic acidosis, ketoacidosis, and renal tubular acidosis. Option E (increased arterial pH; decreased arterial PCO2; decreased serum HCO3 ) is incorrect. These findings are most consistent with a partially compensated primary acute respiratory alkalosis (metabolic acidosis is compensation). Examples include anxiety, a pulmonary embolus, and restrictive lung disease (e.g., sarcoidosis). Option F (increased arterial pH; decreased arterial PCO2; decreased serum HCO ) is incorrect. These findings are most consistent with a partially compensated chronic respiratory alkalosis. Living at high altitudes is the best example of this condition. |
| A 28-year-old man has a family history of sudden cardiac death at a young age (<45 years of age). Physical examination shows a systolic murmur that decreases in intensity when the patient is lying down and increases in intensity when he is sitting up. | Option C (conduction system defects) is correct. The patient has hypertrophic cardiomyopathy (idiopathic hypertrophic subaortic stenosis), which is the most common cause of sudden cardiac death in young people. In some cases, there is an autosomal dominant inheritance pattern. Because of asymmetric hypertrophy of the interventricular septum, the anterior leaflet of the mitral valve is closer to the septum than normal. This narrows the outlet channel for blood flow through the aorta. When systole occurs, the anterior leaflet of the mitral valve is drawn against the interventricular septum, thus obstructing blood flow below the level of the aortic valve. This produces a systolic ejection murmur that is easily confused with aortic stenosis. Aberrant myofibers in the hypertrophied septum and conduction system abnormalities also occur; the latter are responsible for fatal ventricular arrhythmia and sudden death. The murmur intensity decreases (less obstruction) whenever left ventricular volume (preload) is increased. Hence, increased venous return to the right-sided heart (lying down) or drugs that decrease cardiac contractility and heart rate (e.g., b -blockers, calcium channel blockers) decrease murmur intensity. Sitting up reduces venous return to the heart (decreases preload) and intensifies the murmur (greater obstruction). Drugs that have an inotropic effect on the heart (e.g., digitalis) or the patient holding his breath against a closed glottis (Valsalva maneuver) have a similar effect. |
| A 28-year-old man has a family history of sudden cardiac death at a young age (<45 years of age). Physical examination shows a systolic murmur that decreases in intensity when the patient is lying down and increases in intensity when he is sitting up. |
Option A (acute myocardial infarction) is incorrect. Hypertrophic cardiomyopathy is not associated with coronary artery disease. Furthermore, conduction defects do not predispose patients to acute MIs. Option B (congenital bicuspid aortic valve) is incorrect. This congenital anomaly is the most common cause of aortic stenosis in young to middle-aged patients. It predisposes patients to dystrophic calcification of the valve cusps and subsequent reduction in valve orifice area for blood flow out of the aorta. In aortic stenosis, increasing preload increases the intensity of the murmur (increases obstruction), and reducing preload decreases the intensity (lessens obstruction). Option D (dissecting aortic aneurysm) is incorrect. Dissections do not cause sudden death and are not associated with systolic murmurs. Proximal dissections stretch the aortic valve ring, causing aortic regurgitation, which is a diastolic murmur heard after the second heart sound. Furthermore, the orifice to the left subclavian artery is often occluded, leading to a diminished pulse. Option E (mitral valve prolapse) is incorrect. Mitral valve prolapse (MVP) is associated with a midsystolic ejection click followed by a murmur. Except for MVP associated with Marfan syndrome, MVP is not associated with sudden cardiac death. |
| A routine physical examination of an asymptomatic, normotensive 21-year-old African American woman is normal; however, a urinalysis shows red blood cells (RBCs) with no casts. The patient says that she occasionally has had blood in her urine in the past. | Option D (sickle cell preparation) is correct. The patient most likely has sickle cell trait, which causes recurrent microscopic hematuria. Although the percentage of sickle hemoglobin in sickle cell trait is only ~40%, with the remainder representing hemoglobin A, the oxygen tension in the renal medulla is low enough to induce sickling of the RBCs in the peritubular capillaries. This results in microinfarctions in the renal medulla and the potential for renal papillary necrosis and loss of both concentration and dilution of urine. |
| A routine physical examination of an asymptomatic, normotensive 21-year-old African American woman is normal; however, a urinalysis shows red blood cells (RBCs) with no casts. The patient says that she occasionally has had blood in her urine in the past. |
Option A (bone marrow examination) is incorrect. The patient most likely has a mild iron deficiency anemia, which is best diagnosed with a serum ferritin level rather than a bone marrow examination. Furthermore, anemia is not a cause of microhematuria. Option B (cystoscopy) is incorrect. At this point in the patient's work-up, if the sickle cell screen is negative, a cystoscopy may be necessary to determine the cause of the hematuria. Option C (renal biopsy) is incorrect. If the sickle cell screen is negative, a renal biopsy may be necessary to rule out primary renal disease, particularly IgA glomerulonephritis. Option E (no further investigation is necessary) is incorrect. A recurrent history of microhematuria is always cause for concern and should be evaluated. |
| A 67-year-old woman is admitted to the hospital with symptoms of pleuritic chest pain, cough productive of rusty looking sputum containing innumerable neutrophils, and a temperature of 39.2\'b0C (102.5\'b0F). She is an alcoholic. X-ray film of the chest s |
Option E 9Streptococcus pneumoniae) is correct. The x-ray film of the chest shows the presence of an intra-alveolar exudate with lobar or segmental consolidation. S. pneumoniae (pneumococcus) accounts for 90-95% of cases of lobar pneumonia. Alcoholism is a major risk factor for pneumonia and can lead to increased morbidity and mortality. |
| A 67-year-old woman is admitted to the hospital with symptoms of pleuritic chest pain, cough productive of rusty looking sputum containing innumerable neutrophils, and a temperature of 39.2\'b0C (102.5\'b0F). She is an alcoholic. X-ray film of the chest s |
Option A (Haemophilus influenzae) is incorrect. This bacterium more commonly produces bronchopneumonia, which has a patchy distribution of inflammation apparent on a chest x-ray film, although it can occasionally produce a lobar pattern. Option B (Klebsiella pneumoniae) is incorrect. Although this bacterium is the second most common cause of lobar pneumonia, it occurs in a small minority of cases. The exudate in Klebsiella pneumonia tends to be thick, sticky, and often bloody. In addition, this pathogen also tends to be tissue destructive. Option C (Mycoplasma pneumoniae) is incorrect. This bacterium causes atypical pneumonia, which is an interstitial pneumonitis rather than an intra-alveolar infection. Option D (Staphylococcus aureus) is incorrect. This bacterium more commonly produces bronchopneumonia. A chest x-ray film will show a patchy distribution of inflammation, with a tendency to abscess formation. |
| A 58-year-old man with a 35-year history of cigarette smoking complains of weight loss and cough. Physical examination shows absence of sweating on the left forehead and face and ipsilateral lid lag and constriction of the pupil. On auscultation, sibilant | Option B (destruction of the cervical sympathetic plexus by a primary lung cancer) is correct. The patient most likely has a primary squamous cell carcinoma in the left superior pulmonary sulcus. The tumor has invaded and destroyed the cervical sympathetic plexus, producing Horner's syndrome. Horner's syndrome is characterized by ipsilateral lid lag (ptosis), pupil miosis (constriction), and absence of sweating (anhidrosis) on the forehead and face. |
| A 58-year-old man with a 35-year history of cigarette smoking complains of weight loss and cough. Physical examination shows absence of sweating on the left forehead and face and ipsilateral lid lag and constriction of the pupil. On auscultation, sibilant |
Option A (destruction of the brachial plexus by a primary lung cancer) is incorrect. Tumor invasion of the brachial plexus by superior sulcus tumors usually produces ulnar nerve irritation. Option C (extension of a primary lung cancer into the anterior mediastinum) is incorrect. The anterior mediastinum contains the thymus and lymphatic tissue. Tumor invasion of the posterior mediastinum, which contains the sympathetic ganglia and nerves, is responsible for producing Horner's syndrome. Option D (uncal herniation secondary to metastatic disease originating in the lung) is incorrect. Uncal herniation refers to herniation of the medial portion of the temporal lobe through the tentorium cerebelli, leading to compression of the midbrain. It is a complication of cerebral edema from any cause, including metastatic disease to the brain. Uncal herniation commonly is associated with compression of the oculomotor nerve (CN III), which produces lid lag, mydriasis (pupil dilatation), and ophthalmoplegia (eyes deviated downward and outward). |
| A 45-year old woman develops a fever and dyspnea approximately 24-hours postcholecystectomy for acute gangrenous cholecystitis. Physical examination shows decreased percussion, increased tactile fremitus, and decreased breath sounds in the right lower lob | Option A (atelectasis) is correct. The most common cause of fever occurring within the first 24-36 hours after surgery is atelectasis, which refers to either a collapse of previously inflated lungs or incomplete expansion of the lungs on inspiration. Postoperatively, mucus plugs develop in the terminal bronchioles, allowing resorption of air out of the distal respiratory unit through the pores of Kohn. The physical findings of atelectasis are those of a lung consolidation, mainly decreased percussion and increased tactile fremitus (vibration of the chest wall when the patient speaks). The loss of lung mass results in ipsilateral elevation of the diaphragm and inspiratory lag, because the lung is not expanding properly on inspiration. |
| A 45-year old woman develops a fever and dyspnea approximately 24-hours postcholecystectomy for acute gangrenous cholecystitis. Physical examination shows decreased percussion, increased tactile fremitus, and decreased breath sounds in the right lower lob |
Option B (lobar pneumonia) is incorrect. Postoperative pneumonia usually develops 3-10 days after surgery. Option C (lung abscess) is incorrect. Aspiration of oropharyngeal contents, the most common cause of a lung abscess, does not occur within such a short time (24 h) after surgery. The patient usually has a cough productive of foul-smelling sputum due to the presence of aerobes and anaerobes in the abscess. Option D (pulmonary infarction) is incorrect. Pulmonary embolization usually occurs 5-7 days after surgery. In this patient, there is no history of pleuritic chest pain, which is invariably present in a pulmonary infarction. Most pulmonary emboli originate in the femoral vein. Option E (spontaneous pneumothorax) is incorrect. The physical findings are those of a lung consolidation. In a spontaneous pneumothorax, a portion of the lung collapses, which produces hyperresonance to percussion. Similar to atelectasis, however, a spontaneous pneumothorax shows inspiratory lag, decreased breath sounds, and elevated hemidiaphragm. |
| A 3-year-old boy is brought to the pediatrician suffering from fatigue and delayed mental development. Laboratory studies show anemia with fairly pronounced basophilic stippling of the red cells. A radiograph of the femur shows increased density of the ep | Option A (blood analysis, increased serum lead) is correct. Lead poisoning in children is often a subtle problem generally resulting from ingestion of flakes of paint containing lead. Paint now rarely contains lead, but older homes may have numerous coats of lead-containing paint beneath the top layer of paint. Lead is stored in blood, soft tissue, and bones. It produces anemia due to its interference with heme synthesis such that a zinc (rather than an iron-containing protoporphyrin) is formed. The pathogenesis of the effects of lead on the central nervous system is not entirely understood. |
| A 3-year-old boy is brought to the pediatrician suffering from fatigue and delayed mental development. Laboratory studies show anemia with fairly pronounced basophilic stippling of the red cells. A radiograph of the femur shows increased density of the ep |
Option B (blood analysis, saturated iron-binding capacity, increased serum iron) is incorrect. This finding suggests the possibility of iron overload, not lead poisoning. Option C (bone marrow aspiration, megakaryocytopenia) is incorrect. Platelet abnormalities would not be expected in lead poisoning. Because blood studies are sufficient for such a diagnosis, bone marrow studies are not indicated. Option D (chromosome analysis, trisomy 21) is incorrect. Unless Down's syndrome is suggested on the basis of physical findings, this analysis is not indicated. |
| A neonate born at 34 weeks' gestation is of appropriate weight and appears to be healthy. About 1 hour after birth, the infant displays retraction of the ribs and grunting sounds are heard during each respiratory cycle. Over the next several hours, the in | Option B (lack of pulmonary surfactant) is correct. This is a classic presentation of idiopathic respiratory distress syndrome (RDS) due to lack of formation of pulmonary surfactant by type II pneumocytes. Histologic examination of the lungs at this time would show hyaline membranes lining the alveolar ducts. The increased work of respiration causes exhaustion of the infant, resulting in decreased ventilation and increased PaCO2. Multiple foci of atelectasis produce ventilation/perfusion (V/Q) ratios near 0, which causes venous dilution of oxygenated blood, producing a decline in PaO2 |
| A neonate born at 34 weeks' gestation is of appropriate weight and appears to be healthy. About 1 hour after birth, the infant displays retraction of the ribs and grunting sounds are heard during each respiratory cycle. Over the next several hours, the in |
Option A (aspiration of meconium) is incorrect. Meconium aspiration is associated with fetal distress. It may cause immediate difficulties with respiration after birth, but it is not expected to cause the usual progression of idiopathic respiratory distress syndrome (RDS). Option C (in utero infection with cytomegalovirus) and Option E (in utero infection with Toxoplasma gondii) are incorrect. Although pneumonitis is frequently seen with TORCH infections (toxoplasmosis, rubella, cytomegalovirus, herpes simplex), it would not be expected to produce respiratory distress syndrome (RDS). Option D (in utero infection with parvovirus) is incorrect. Parvovirus infection causes hydrops fetalis and spontaneous abortion. |
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The 6-mm lesion shown in the photomicrograph was removed from the sigmoid colon of a 49-year-old man. A molecular examination of the DNA of the cells of the lesion would show A. activation of K- B. deletion of DCC C. hypomethylation D. inactivati |
Option C (hypomethylation) is correct. Hypomethylation of DNA is one of the earliest genetic changes in the development of colonic cancer, and may be present when no histologic abnormalities are detectable. As additional genetic errors occur, the cells will become more atypical. |
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The 6-mm lesion shown in the photomicrograph was removed from the sigmoid colon of a 49-year-old man. A molecular examination of the DNA of the cells of the lesion would show A. activation of K- B. deletion of DCC C. hypomethylation D. inactivati |
Option A (activation of K-) is incorrect. Although K- is the most commonly activated oncogene in the development of colon cancer, its activation is found in about only 10% of tumors less than 1 cm in diameter. Option B (deletion of DCC) is incorrect. DCC is no longer believed to play a role in the oncogenesis of colon cancer. It may be a marker for another, as yet uncloned, tumor suppressor gene on the same chromosome. Option D (inactivation of RB1) is incorrect. RB1 is not one of the tumor suppressor genes associated with the development of colon cancer. Option E (loss of p53) is incorrect. In 70\\'9680% of cases of colon cancer, p53 is absent or mutated; it appears infrequently in adenomas. |
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A 27-year-old man is a diagnosed with a diffuse large cell lymphoma. Genetic analysis of DNA from the lymphoma cells shows rearrangement of the immunoglobulin genes. Which of the following is the most likely origin of this lymphoma? A. B-cell lymphoma |
Option A (B-cell lymphoma) is correct. Somatic rearrangement of the immunoglobulin genes marks this lesion as a lymphoma of B cell origin. Lymphoma is a monoclonal lesion, so all of the tumor cells exhibit identical patterns of immunoglobulin gene rearrangement. |
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A 27-year-old man is a diagnosed with a diffuse large cell lymphoma. Genetic analysis of DNA from the lymphoma cells shows rearrangement of the immunoglobulin genes. Which of the following is the most likely origin of this lymphoma? A. B-cell lymphoma |
Option B (histiocytic lymphoma) is incorrect. True histiocytic lymphomas are uncommon, and do not show rearrangement of the immunoglobulin genes. Option C (natural killer cell lymphoma) is incorrect. NK cell lymphoma is a type of lymphoma classified as non\'96B- and non\'96T-cell lymphomas that were originally known as null cell lymphomas. They do not exhibit the gene rearrangement characteristic of T cell or B cell origin. Option D (T-cell lymphoma) is incorrect. Gene rearrangements are characteristic of T-cell lymphomas, but these changes do not involve the immunoglobulin genes. |
| A 37-year-old woman with a 5-year history of Raynaud's phenomenon, increasing dysphagia, and vague abdominal pain undergoes further testing for autoimmune disease. An immunofluorescent antinuclear antibody (ANA) test shows a nucleolar pattern with a high | Option B (fibrosis of the dermis, thinning of the epidermis, and thickening of the arterioles) is correct. These pathologic findings are consistent with the diagnosis of progressive systemic sclerosis. The clinical presentation of Raynaud's phenomenon and dysphagia, along with the laboratory finding of a strongly positive ANA with a nucleolar pattern, are also suggestive of progressive systemic sclerosis. |
| A 37-year-old woman with a 5-year history of Raynaud's phenomenon, increasing dysphagia, and vague abdominal pain undergoes further testing for autoimmune disease. An immunofluorescent antinuclear antibody (ANA) test shows a nucleolar pattern with a high |
Option A (fibrinoid necrosis of the vasculature) is incorrect. This change is more suggestive of systemic lupus erythematosus (SLE), in which an acute necrotizing vasculitis affects small arteries and arterioles, particularly of the skin and muscles. Option C (liquefactive necrosis of the basal layer of the epidermis) is incorrect. This change is suggestive of SLE. Classically, skin lesions show liquefactive degeneration of the basal epidermal layer. Option D (necrotizing inflammation of the small arterioles) is incorrect. Such involvement suggests polyarteritis nodosa, which affects small- to medium-sized arteries in any organ (e.g., kidneys, heart, liver). |
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The figure shows a lung removed at autopsy from a 29-year-old man. Which of the following was most likely involved in the initial injury? A. Alveolar type II pneumonocytes B. Capillary endothelium C. Clara cells D. Pleural mesothelium |
Option B (capillary endothelium) is correct. The photograph shows a lung in the fibrotic stage of adult respiratory distress syndrome (ARDS). In most cases of ARDS, the initial injury involves the capillary endothelium. |
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The figure shows a lung removed at autopsy from a 29-year-old man. Which of the following was most likely involved in the initial injury? A. Alveolar type II pneumonocytes B. Capillary endothelium C. Clara cells D. Pleural mesothelium |
Option A (alveolar type II pneumonocytes), Option C (Clara cells), and Option D (pleural mesothelium) are incorrect. In a small minority of cases of ARDS, the original injury may involve alveolar type I pneumonocytes. |
| A 24-year-old man has a history of fever, weight loss, hypertension, and abdominal pain. Stool and urinalysis are positive for the presence of blood. Several nodular skin lesions are found. A biopsy shows necrotizing arteritis involving medium-sized muscu | Option B (polyarteritis nodosa) is correct. Necrotizing inflammation of affected arteries is characteristic of polyarteritis nodosa, a disease that typically involves medium-sized muscular arteries. This disease may involve fever and weight loss, and hypertension is common. Gastrointestinal lesions are the source of the abdominal pain. The disease may affect individuals of any age. |
| A 24-year-old man has a history of fever, weight loss, hypertension, and abdominal pain. Stool and urinalysis are positive for the presence of blood. Several nodular skin lesions are found. A biopsy shows necrotizing arteritis involving medium-sized muscu |
Option A (Kawasaki disease) is incorrect. This condition involves arteries of all sizes. However, it usually occurs in infants and children. Option C (syphilis) is incorrect. Syphilis causes an arteritis, but characteristically it is endarteritis with an infiltrate that is rich in plasma cells. Option D (systemic lupus erythematosus) is incorrect. SLE commonly causes a vasculitis that more typically involves the small arteries and arterioles. Option E (Takayasu's arteritis) is incorrect. This granulomatous arteritis usually involves the origin of the great vessels at the aortic arch. |
| A total thyroidectomy is performed on a 42-year-old woman with a thyroid mass that appears to be encapsulated. There is evidence of both recent and past hemorrhage and numerous small, follicle-like structures composed of very uniform-appearing cells. Whic | Option C (extension through the capsule) is correct. Invasion through the capsule of the tumor is one of the core characteristics used to determine if a follicular neoplasm of the thyroid is benign or malignant. Another characteristic is invasion of the tumor into the vasculature. |
| A total thyroidectomy is performed on a 42-year-old woman with a thyroid mass that appears to be encapsulated. There is evidence of both recent and past hemorrhage and numerous small, follicle-like structures composed of very uniform-appearing cells. Whic |
Option A (absence of papillary growth) and Option D (microfollicular pattern) are incorrect. These choices would only classify the lesion as a follicular neoplasm. Option B (absence of psammoma bodies) is incorrect. This would confirm that most likely this tumor is not a papillary neoplasm. Option E (presence of hemorrhage) is incorrect. Hemorrhage is a frequent occurrence in follicular neoplasms of the thyroid, but it would not be a clue in determining if the tumor is benign or malignant. |
| An otherwise healthy 24-year-old woman sees her physician because of "lumps" in her neck. She has no significant family history. Her vital signs are normal, with no suggestion of fever. On palpation of the abdomen, there is no sign of organomega | Option B (typically arises in a single axial group of lymph nodes) is correct. Hodgkin's disease usually arises within a single group of nodes and then spreads contiguously from that point. |
| An otherwise healthy 24-year-old woman sees her physician because of "lumps" in her neck. She has no significant family history. Her vital signs are normal, with no suggestion of fever. On palpation of the abdomen, there is no sign of organomega |
Option A (almost always involves multiple peripheral groups of lymph nodes), Option C (typically involves extensive extranodal areas), Option D (typically involves mesenteric lymph nodes and Waldeyer's ring), and Option E (usually skips over groups of nodes) are incorrect. All of these characteristics are more commonly found in patients with non-Hodgkin's lymphoma. |
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The photomicrograph shows the lung of a 73-year-old woman. The most common cause of the pulmonary finding shown in the figure is A. hepatic failure B. ionizing radiation C. left ventricular failure D. nephrotic syndrome E. paraquat exposure |
Option C (left ventricular failure) is correct. The photomicrograph shows the lung of a patient with pulmonary edema. The most common cause of this disease is an increase in hydrostatic pressure within the pulmonary vasculature. Of the listed causes, left ventricular failure would be the most likely possibility. |
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The photomicrograph shows the lung of a 73-year-old woman. The most common cause of the pulmonary finding shown in the figure is A. hepatic failure B. ionizing radiation C. left ventricular failure D. nephrotic syndrome E. paraquat exposure |
Option A, Option B, Option D, and Option E are incorrect. Refer to the discussion for Option C. |
| An endometrial biopsy of a 47-year-old woman with a history of irregular vaginal bleeding shows a well-differentiated adenocarcinoma of the endometrium. A hysterectomy confirms tumor involvement of the corpus of the uterus and the cervix. Which of the fol | Option A (history of anovulatory menstrual cycles) is correct. A history of irregular vaginal bleeding corroborates anovulatory menstrual cycles and is strongly associated with the development of endometrial cancer, probably because of prolonged estrogen stimulation. |
| An endometrial biopsy of a 47-year-old woman with a history of irregular vaginal bleeding shows a well-differentiated adenocarcinoma of the endometrium. A hysterectomy confirms tumor involvement of the corpus of the uterus and the cervix. Which of the fol |
Option B (history of cervical human papillomavirus infection) is incorrect. There is no known association between HPV and endometrial carcinoma. Option C (multiple pregnancies) is incorrect. Nulliparity has an association with the development of endometrial carcinoma Option D (thin body habitus) is incorrect. Excess body fat is associated with endometrial carcinoma due to its conversion of androgen precursors into estrogen. |
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As a result of the decreased incidence of patients with chronic rheumatic fever, consequent damage to the cardiac valves has diminished. The most common antecedent condition leading to infectious myocarditis presently is A. congenital heart disease B. en |
Option A(congenital heart disease) is correct. Rheumatic heart disease was once considered the most common condition that could lead to infectious endocarditis. Presently, congenital lesions, particularly those that produce a "jet" effect such as a small ventricular septal defect, are more common and are a risk factor for infective endocarditis. |
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As a result of the decreased incidence of patients with chronic rheumatic fever, consequent damage to the cardiac valves has diminished. The most common antecedent condition leading to infectious myocarditis presently is A. congenital heart disease B. en |
Option B (endocardial trauma), Option C (hypercoagulable state), Option D (leukemia), and Option E (mucin-producing adenocarcinoma) are incorrect. All of these conditions are associated with noninfective endocarditis, which may produce verrucous lesions on the margins of the heart valves. These lesions embolize but are not caused by an infectious organism. |
| Unilateral facial dropping (entire 1/2 of face) | Bell's palsy (LMN CN VII palsy); if only lower half of one side of face affected it's an UMN lesion; bilateral = lyme dz or guillan-barre. |
| Two months ago, a 19-year-old man was brought to the emergency department following an automobile accident in which he sustained severe lacerations and a ruptured spleen. He immediately received four units of packed red blood cells. He now has developed m | Option C (hepatitis C) is correct. HCV has become the major cause of transfusion-related hepatitis since adequate screening methods for HBV have been developed. HCV was previously referred to as non-A, non-B hepatitis or chronic active hepatitis. |
| Two months ago, a 19-year-old man was brought to the emergency department following an automobile accident in which he sustained severe lacerations and a ruptured spleen. He immediately received four units of packed red blood cells. He now has developed m |
Option A (hepatitis A) is incorrect. HAV infection is virtually always transmitted through the fecal-oral route. Option B (hepatitis B) is incorrect. HBV is a blood-borne disease and is no longer a major source of post-transfusion hepatitis since adequate screening methods for HBV have been developed. At present, HBV is transmitted most often by intravenous drug users using shared needles and through intimate sexual contact. Option D (hepatitis D) is incorrect. HDV requires the presence of HBV infection, because the HDV is defective and cannot replicate on its own. Option E (hepatitis E) is incorrect. HEV, an enteric virus, causes hepatitis via the fecal-oral route and is found primarily in developing countries. |
| For the past 6 months, an 18-year-old woman has had diarrhea, a fever, and cramping and left lower quadrant pain. Flexible sigmoidoscopy shows mucosal ulceration in the sigmoid colon. A biopsy shows transmural inflammation with occasional granulomas. Whic | Option E (presence of transmural inflammation with granular formation) is correct. Ulcerative colitis is essentially a disease of the mucosa, whereas Crohn's disease involves all layers of the bowel wall. A biopsy shows that this patient has transmural inflammation with occasional granulomas. |
| For the past 6 months, an 18-year-old woman has had diarrhea, a fever, and cramping and left lower quadrant pain. Flexible sigmoidoscopy shows mucosal ulceration in the sigmoid colon. A biopsy shows transmural inflammation with occasional granulomas. Whic |
Option A (history of fever) is incorrect. Fever is a nonspecific symptom and can be associated with both ulcerative colitis and Crohn's disease. Option B (history of prolonged diarrhea) is incorrect. Diarrhea is a symptom of both ulcerative colitis and Crohn's disease. Option C (involvement limited to the colon) is incorrect. Although ulcerative colitis is usually limited to the colon, this restriction does not differentiate between ulcerative colitis and Crohn's disease. Involvement of other parts of the gastrointestinal system, such as the small bowel and stomach, point to Crohn's disease. Option D (presence of gross mucosal ulcerations) is incorrect. Both ulcerative colitis and Crohn's disease, as well as some infectious processes such as amebiasis, can cause mucosal ulceration. |
| A tall, obese 13-year-old boy has bilateral gynecomastia, decreased testicular volume for his age, and sparse axillary and pubic hair. He had the usual childhood infections, except for mumps. A CT scan of the pituitary gland is normal. A buccal smear prep | Option A (high FSH; high LH; low testosterone) is correct. The patient has Klinefelter's syndrome, which is a sex-chromosome disorder with 47 chromosomes (XXY). These patients have one Barr body, because one of the two X chromosomes is randomly inactivated. Abnormal numbers of chromosomes are usually due to nondisjunction in the first step of meiosis. Most patients are diagnosed in adolescence, when males fail to show appropriate secondary sex characteristics of puberty. Physical examination shows disproportionately long arms and legs (eunuchoid proportions), decreased testicular volume for age, sparse axillary and pubic hair, and gynecomastia; the last two findings are related to hyperestrinism. Both testicles are atrophic, with atrophy and fibrosis of the seminiferous tubules and no evidence of spermatogenesis (azoospermia). There is hyperplasia of the Leydig cells. The absence of Sertoli cells in the fibrosed seminiferous tubules results in decreased synthesis of the hormone inhibin, which normally has a negative feedback relationship with FSH. Hence, FSH levels in Klinefelter's syndrome are markedly elevated. Because FSH normally increases the synthesis of aromatase in Leydig cells, hyperplasia of the Leydig cells causes an even greater conversion of testosterone into estradiol than normal. Therefore, the patient develops signs of hyperestrinism and hypogonadism, due to low testosterone levels. Decreased synthesis of testosterone, which normally has a negative feedback on LH, leads to an increase in LH. |
| A tall, obese 13-year-old boy has bilateral gynecomastia, decreased testicular volume for his age, and sparse axillary and pubic hair. He had the usual childhood infections, except for mumps. A CT scan of the pituitary gland is normal. A buccal smear prep |
Option B (high FSH; normal LH; normal testosterone) is incorrect. These findings are consistent with pure seminiferous tubule failure. Loss of inhibin leads to an increase in FSH. Because Leydig cells are functional, serum LH and testosterone are normal. Option C (low FSH; low LH; and low testosterone) is incorrect. These findings are consistent with hypopituitarism, where FSH and LH are decreased, with low LH leading to decreased testosterone synthesis. Option D (normal FSH; high LH; low testosterone) is incorrect. These findings are consistent with a pure Leydig cell failure, where a decrease in testosterone leads to an increase in LH. FSH is normal, because the seminiferous tubules are normal. |
| A 62-year-old man who has smoked three packs of cigarettes daily for 40 years has shortness of breath on exertion. He is thin with a somewhat expanded barrel-shaped chest and ribs that tend to be somewhat horizontal. He breathes through pursed lips. He is | Option A (airway obstruction due to a reduction in elastic recoil of the lung) is correct. The patient has emphysema as a result of his history of cigarette smoking for 40 years. Smoking has resulted in the release of an excess of elastase by inflammatory cells (neutrophils and macrophages) in the lungs, causing destruction of the normal architecture of the pulmonary parenchyma. The result is a loss of normal lung elastance and an increase in compliance. Elastic recoil is one of the major sources of energy for movement of air out of the lung during expiration. When it is reduced, the pressure surrounding the small airways becomes greater than the pressure within them, resulting in dynamic collapse of the airway and hence obstruction to airflow in expiration. This normally occurs toward the end of expiration, but in patients with emphysema, it occurs too early, trapping air and increasing residual volume and reducing the FEV1. |
| A 62-year-old man who has smoked three packs of cigarettes daily for 40 years has shortness of breath on exertion. He is thin with a somewhat expanded barrel-shaped chest and ribs that tend to be somewhat horizontal. He breathes through pursed lips. He is |
Option B (airway obstruction due to severe bronchospasm) is incorrect. Bronchospasm is one of the major causes of airway obstruction in bronchial asthma and sometimes in chronic bronchitis. It does not play a role in patients with "pure" emphysema. Option C (bronchiolar obstruction due to mucous gland hyperplasia and mucous secretion) is incorrect. Excessive secretion of bronchial mucus would cause obstruction in a patient with chronic bronchitis. Option D (inability to use the accessory muscles of respiration in expiration adequately) is incorrect. Such inability might be a cause of respiratory difficulty in a patient with a neuromuscular problem, but would not be a factor in a typical patient with emphysema. Option E (ventilation/perfusion ratio <1.0) is incorrect. A change in V/Q (ventilation/perfusion) would not explain the diminished FEV1, which is a problem with lung mechanics. |
| A 45-year-old woman with a history of mitral stenosis and chronic arrhythmia dies suddenly at her home. At autopsy, a wedge-shaped hemorrhagic lesion is seen at the periphery of the temporal lobe. The mechanism for the temporal lobe lesion is most closely | Option B (embolic occlusion of a cerebral artery) is correct. Patients with mitral stenosis develop left atrial dilatation and produce thrombi due to stasis of blood in the chamber. Furthermore, left atrial dilatation predisposes to atrial fibrillation. The combination of a thrombus in the left atrium and atrial fibrillation results in multisystem embolic disease with infarctions. When emboli from the heart disseminate to the brain, they usually enter the middle cerebral artery. Occlusion of the artery results in wedge-shaped infarction extending to the periphery of the brain. When the embolus dissolves, reperfusion of the infarcted area causes a hemorrhagic infarction. An infarction in the brain is an example of liquefactive (not coagulative) necrosis. |
| A 45-year-old woman with a history of mitral stenosis and chronic arrhythmia dies suddenly at her home. At autopsy, a wedge-shaped hemorrhagic lesion is seen at the periphery of the temporal lobe. The mechanism for the temporal lobe lesion is most closely |
Option A (atherosclerosis of the internal carotid artery) is incorrect. An atherosclerotic stroke is usually due to a platelet thrombus overlying an atherosclerotic plaque near the bifurcation of the internal carotid artery. This produces a pale infarction of the ipsilateral brain that extends to the periphery of the brain. However, unlike an embolic stroke, reperfusion is less likely to occur, so the infarct remains pale due to the lack of blood flow to the area. Option C (intracerebral hematoma) is incorrect. Intracerebral hematomas usually are caused by hypertension. Long-standing hypertension leads to the formation of Charcot-Bouchard macroaneurysms of the lenticulostriate vessels, which supply the putamen and thalamus. When these aneurysms rupture, they produce an intracerebral hematoma (not an infarction), most commonly in the basal ganglia area of the brain. Other areas where hematomas can form in a hypertensive bleed are the pons and cerebellar hemispheres. Option D (neoplastic transformation of astrocytes) is incorrect. Astrocytomas are neoplasms arising from astrocytes. Low-grade astrocytomas (grades I and II) are benign; high-grade astrocytomas (e.g., glioblastoma multiforme) are malignant. Glioblastoma multiforme is the most common primary brain tumor found in adults and is characterized by hemorrhagic necrosis. The frontal lobes usually are involved, and the tumor frequently extends across the corpus callosum to the contralateral lobe. Option E (rupture of a congenital aneurysm) is incorrect. Congenital aneurysms in the brain usually develop at the junction of the anterior communicating artery with the anterior cerebral artery or the posterior communicating artery with the posterior cerebral artery. Loss of internal elastic lamina and smooth muscle at the branching points of the vessel occurs, predisposing to berry aneurysm formation. When these rupture, the blood usually enters the subarachnoid space, causing a severe occipital headache and loss of consciousness. |
| A 40-year-old woman has enlarged lymph nodes in the axillae, groin, and cervical triangles. Biopsy of an axillary node shows complete effacement of the architecture of the nodes by nodular aggregates of lymphoma cells. Which of the following is the cell l | Option A (B cell) is correct. The woman has follicular (nodular) lymphoma, a non-Hodgkin's (NHL) lymphoma that expresses B cell cluster of differentiation (CD) markers. All follicular (nodular) lymphomas are of B cell lineage. |
| A 40-year-old woman has enlarged lymph nodes in the axillae, groin, and cervical triangles. Biopsy of an axillary node shows complete effacement of the architecture of the nodes by nodular aggregates of lymphoma cells. Which of the following is the cell l |
Option B (CD4+ T cell), Option C (CD8+ T cell), and Option D (histiocyte) are incorrect. Refer to the discussion for Option A. Option E (natural killer cell) is incorrect. NK cells comprise 10\'9615% of peripheral blood lymphocytes. They lack both T cell and B cell markers. |
| The mother of an atopic 8-year-old boy notices that her son's face and legs began to swell over the past few days. She assumes that the boy is experiencing a reaction to something he ate, so she immediately takes him to the emergency department. Physical | Option A (fusion of the podocytes) is correct. The patient has the classic findings of nephrotic syndrome, which, in children, is usually due to lipoid nephrosis (minimal change disease). Preceding upper respiratory infection, atopy, nonsteroidal anti-inflammatory drugs, and Hodgkin's disease all have been implicated in the pathogenesis of the disease. The gold standard for diagnosis of nephrotic syndrome is a 24-hour urine protein level >3.5 g (<150 mg/24 h). In lipoid nephrosis, a T-cell immune reaction against visceral epithelial cells causes loss of the negative charge of the glomerular basement membrane (called polyanion loss), which results in a selective loss of albumin in the urine. Because the plasma albumin concentration is responsible for 80% of the oncotic pressure, hypoalbuminemia results in leakage of a protein-poor transudate from the vascular compartment into the interstitial tissue (pitting edema) and body cavities (ascites). Furthermore, hypoalbuminemia stimulates increased liver synthesis of cholesterol and subsequent hypercholesterolemia (type II hyperlipoproteinemia). Cholesterol leaks into the urine, producing fatty casts that polarize and often show "Maltese crosses." Lipid stains are positive in the glomeruli and renal tubular cells; however, no proliferative or glomerular basement membrane changes are seen in the glomeruli. Immunofluorescent stains are negative. Electron microscopy shows fusion of the podocytes, which is a universal finding in any nephrotic syndrome. Lipoid nephrosis is not considered an immunocomplex-mediated disease, since no electron-dense deposits are found in the glomeruli. Children respond extremely well to steroid therapy. |
| The mother of an atopic 8-year-old boy notices that her son's face and legs began to swell over the past few days. She assumes that the boy is experiencing a reaction to something he ate, so she immediately takes him to the emergency department. Physical |
Option B (intramembranous electron-dense deposits) is incorrect. These findings are consistent with type II membranoproliferative glomerulonephritis ("dense deposit" disease), which produces nephrotic syndrome. An autoantibody against C3, called the C3 nephritic factor, causes continual activation of the alternative pathway, leading to low complement levels. Option C (mesangial electron-dense deposits) is incorrect. These findings are consistent with IgA glomerulonephritis (Berger's disease), which is the most common type of glomerulonephritis. Children have recurrent macrohematuria (usually following respiratory infections), whereas adults have recurrent microhematuria. Option D (subendothelial electron-dense deposits) is incorrect. These findings are seen in type IV proliferative glomerulonephritis in patients with systemic lupus erythematosus and in type I membranoproliferative glomerulonephritis. Option E (subepithelial electron-dense deposits) is incorrect. These findings are seen in poststreptococcal glomerulonephritis and diffuse membranous glomerulonephritis, which is the most common cause of nephrotic syndrome in adults. |
| A 32-year-old woman has a family history of a high incidence of neoplasia involving multiple organ systems. She undergoes genetic screening for several tumor suppressor genes and oncogenes and is found to have Li-Fraumeni syndrome. The genetic defect asso | Option C (P53) is correct. Loss of one of the alleles of the P53 gene is the basis of the Li-Fraumeni syndrome. Patients with this syndrome have an increase in the development of malignant neoplasms arising in various anatomic locations. P53, a tumor suppressor gene that also has oncogene-like properties when mutated, produces an abnormal gene product that is not degraded with normal speed. Patients with a mutated or missing P53 gene have an increased risk of developing malignancies in various tissues. |
| A 32-year-old woman has a family history of a high incidence of neoplasia involving multiple organ systems. She undergoes genetic screening for several tumor suppressor genes and oncogenes and is found to have Li-Fraumeni syndrome. The genetic defect asso | Option A ( bcl-2), Option B (NF-1), Option D (RB), and Option E (WT1) are incorrect. The oncogene bcl-2 is associated with prevention of apoptosis. NF-1, RB, and WT1 are tumor suppressor genes associated with neurofibromatosis, retinoblastoma, and Wilms' tumor of the kidney, respectively. |
| A 49-year-old man is brought to the emergency department about 6 hours after the onset of crushing chest pain. An ECG is suggestive of acute myocardial infarction (MI), and a troponin-I test is positive. He suddenly develops ventricular arrhythmia and des | Option C (8 hours) is correct. The typical signs of coagulative necrosis, including nuclear pyknosis, karyolysis, karyorrhexis, and increased cytoplasmic eosinophilia, appear 8-12 hours after infarction occurs. |
| A 49-year-old man is brought to the emergency department about 6 hours after the onset of crushing chest pain. An ECG is suggestive of acute myocardial infarction (MI), and a troponin-I test is positive. He suddenly develops ventricular arrhythmia and des |
Option A (20 minutes) is incorrect. The changes that occur in such a short period of time are only ultrastructural (e.g., mitochondrial swelling).Option B (2 hours) is incorrect. In 2 hours, a few "wavy" fibers are visible at the margin of the infarct. Option D (24 hours) is incorrect. At 24 hours, both the microscopic and gross changes of necrosis would be discernible. At 48 hours, an influx of neutrophils would also be present. Option E (72 hours) is incorrect. At 72 hours, the influx of neutrophils would be at its height, and signs of dissolution of the necrotic heart muscle would be evident. |
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A 30-year-old woman fears that she will develop ovarian cancer because of her family history and is tested for the BRCA1 gene. This gene has a strong association with which of the following ovarian neoplasms? A. Dysgerminoma B. Mixed M\'fcllerian tum |
Option C (serous cystadenocarcinoma) is correct. In women who are positive for the BRCA1 gene, the vast majority of ovarian tumors are serous cystadenocarcinomas. A woman who has a family history of ovarian cancer would be at risk for carrying the BRCA1 gene. |
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A 30-year-old woman fears that she will develop ovarian cancer because of her family history and is tested for the BRCA1 gene. This gene has a strong association with which of the following ovarian neoplasms? A. Dysgerminoma B. Mixed M\'fcllerian tum |
Option A, Option B, and Option D are incorrect. Refer to the discussion for Option C. |
| A 2-day-old neonate with respiratory distress syndrome (RDS) has moderately severe hypoxemia. On auscultation, dry inspiratory crackles are heard in the lungs and a continuous harsh murmur is heard over the entire precordium. Which of the following sets o | Option C (RA 75, RV 75, PA 80, PV 95, LV 95, A 95) is correct. The patient has the classic machinery murmur (continuous murmur) of a patent ductus arteriosus (PDA). Because the neonate has hypoxemia (low arterial PO2) secondary to RDS, the ductus has no stimulus to close. Congenital heart diseases often have shunts between chambers or vessels. The pressure in the chamber or vessel determines the direction of blood flow. When oxygenated blood (SaO2 95%) is shunted into a chamber or vessel with venous blood (SaO2 75%), there is a step-up of SaO2 (~80%) in the venous blood; this is known as a left-to-right shunt. Similarly, when venous blood is shunted into a chamber or vessel with oxygenated blood, there is a step-down of the SaO2 (~80%) leading to clinical evidence of cyanosis; this is known as a right-to-left shunt. In PDA, blood initially flows from the aorta (where pressure is high), through the patent ductus arteriosus, and into pulmonary artery (where pressure is low), a left-to-right shunt; hence there is a step-up of the SaO2 in the pulmonary artery. |
| A 2-day-old neonate with respiratory distress syndrome (RDS) has moderately severe hypoxemia. On auscultation, dry inspiratory crackles are heard in the lungs and a continuous harsh murmur is heard over the entire precordium. Which of the following sets o |
Option A (RA 75, RV 80, PA 80, PV 95, LV 95, A 95) is incorrect. A step-up of SaO2 in the right ventricle and pulmonary artery is consistent with a ventricular septal defect (VSD, or left-to-right shunt), which is the most common congenital heart disease. If a VSD is left uncorrected, the volume overload in the right side of the heart due to the left-to-right shunt leads to pulmonary hypertension. This is followed by right ventricular hypertrophy and eventual reversal of the shunt (right-to-left), producing clinical evidence of cyanosis, or Eisenmenger's syndrome. Option B (RA 80, RV 80, PA 80, PV 95, LV 95, A 95) is incorrect. A step-up of the SaO2 in the right atrium, right ventricle, and pulmonary artery is consistent with an atrial septal defect (ASD, or left-to-right shunt), which is most often the result of a patent foramen ovale. Eisenmenger's syndrome also may occur in an ASD (refer to the discussion for Option A). Option D (RA 75, RV 75, PA 75, PV 95, LV 80, A 80) is incorrect. A step-down of the SaO2 in the left ventricle and aorta is consistent with tetralogy of Fallot (right-to-left shunt), which is the most common type of cyanotic congenital heart disease. It consists of an overriding aorta (least common defect), VSD, infravalvular pulmonary stenosis, and right ventricular hypertrophy. The degree of pulmonic stenosis determines the severity of the right-to-left shunt. If the stenosis is not severe, then most of the venous blood enters the pulmonary artery and is oxygenated; hence the patient is often acyanotic. However, when the stenosis is severe, most of the venous blood is shunted through the VSD into the left ventricle (right-to-left shunt), leading to cyanosis. Coexisting PDA and ASD are cardioprotective in a tetralogy. A PDA allows some of the unoxygenated blood in the aorta to reenter the pulmonary artery for oxygenation in the lungs. An ASD allows oxygenated blood from the left atrium to shunt into the right atrium and step-up the SaO2 in the right side of the heart. |
| A 28-year-old man who was hit by a car while crossing the street is immediately taken by ambulance to a nearby hospital. Physical examination shows diminished pulse, cold, clammy skin, and blood pressure of 60/40 mm Hg. Additional findings include an open | Option A (low hemoglobin and low hematocrit) is correct. The patient is in hypovolemic shock secondary to blood loss from the open femoral fracture and a possible ruptured spleen. Initially, loss of whole blood does not alter the Hgb and Hct concentrations because equal amounts of red blood cells (RBCs) and plasma are lost. Within a few hours, however, sodium-containing fluid reabsorbed by the kidneys, along with fluid from the interstitial space, is added to the vascular compartment to restore volume. This uncovers the RBC deficit, leading to a decrease in the Hgb and Hct. If the patient is not transfused with packed RBCs, over the next few weeks to months, the bone marrow replaces the RBC deficit until the Hgb and Hct return to the normal range. However, if a patient with massive blood loss is infused with 0.9% normal saline to increase the blood pressure, the RBC deficit is uncovered immediately and the expected decrease in Hgb and Hct is noted in a complete blood cell count. |
| A 28-year-old man who was hit by a car while crossing the street is immediately taken by ambulance to a nearby hospital. Physical examination shows diminished pulse, cold, clammy skin, and blood pressure of 60/40 mm Hg. Additional findings include an open |
Option B (low mean corpuscular volume) is incorrect. The size of the RBCs is not altered by the immediate loss of RBCs. Option C (low serum glucose concentration) is incorrect. The patient received 0.9% normal saline without glucose. Option D (low serum sodium concentration) is incorrect. The concentration of sodium remains the same because 0.9% normal saline is isotonic with plasma. Option E(low white blood cell count) is incorrect. Trauma causes the release of catecholamines, which decrease adhesion molecule synthesis, causing release of the marginating neutrophil pool in the peripheral blood into the circulating pool. This results in an absolute neutrophilic leukocytosis. |
